What a volume calculator does
A volume calculator finds how much three-dimensional space a solid takes up. This page gives each of eleven shapes its own calculator: sphere, cone, cube, cylinder, rectangular box, capsule, spherical cap, conical frustum, ellipsoid, square pyramid and hollow tube. Work down the page or jump straight to the shape you need.
For every shape you enter the dimensions, choose a unit for each one (millimetres to miles, including inches, feet and yards) and read the volume in the unit you pick, plus litres, cubic metres, cubic feet and US and UK gallons. Mixing units is fine, for example a radius in centimetres and a height in metres.
It is useful for tanks, containers, concrete, soil and packaging as well as for school geometry.
Volume is the amount of three-dimensional space a solid occupies, measured in cubic units. It is different from area, which measures a flat surface in square units: the area calculator handles floors and bases, and the surface area calculator gives the outer skin of a solid, useful for paint or coating. Use volume when the question is “how much does it hold?” or “how much material fills it?”.
Capacity is the volume of the inside of a container, so for tanks, buckets and boxes measure the inside dimensions. For a solid made of several simple parts, such as a silo (a cylinder topped by a cone), calculate each part and add the results; for a solid with a hole, subtract the hole. Irregular objects can be measured by the water they displace.
- Students and teachers checking geometry homework against the formula and working.
- DIY builders and gardeners estimating soil, gravel or concrete.
- Anyone sizing a tank, pipe, bucket or container, or converting a volume to litres or gallons.
How to use the volume calculators
- Find your shape in the list above, or use the “Choose a shape” buttons to jump to it.
- Type each dimension and pick its unit. Units can differ from one dimension to the next.
- Choose the unit for the answer in “Show volume in”, or leave it on the default.
- Press Calculate. The result shows the formula, your numbers put into it and the answer, together with litres, cubic metres, cubic feet and US and UK gallons.
- Dimensions
- Radius, height, edge lengths and so on. Each one has its own unit menu, and the labels match the letters on the diagram beside the inputs.
- Length unit (per dimension)
- mm, cm, m, km, in, ft, yd or mi, chosen separately for every dimension.
- Show volume in
- The unit of the headline answer: cubic units, litres, millilitres, or US or UK gallons. The default is the cube of the first length unit.
- Spherical cap inputs
- Enter exactly two of the sphere radius (R), cap height (h) and cap base radius (a) and leave the third blank.
Each dimension is converted to metres, the standard formula for the shape is applied, and the volume in cubic metres is then converted into the unit you chose and into litres, cubic feet and US and UK gallons. The result panel shows the formula, your numbers put into it and the answer, so you can follow the working. Entries must be positive numbers; the tube needs an inner radius smaller than its outer radius, and a spherical cap cannot be taller than the sphere’s diameter.
Volume formula, worked example and tips for every shape
The sections below follow the same order as the calculators. Each one explains the shape, gives the formula, works through an example you can repeat in the calculator, and lists practical tips and common mistakes. π is used at full precision (about 3.14159265), and a circle’s radius is half its diameter; the circle calculator converts between radius, diameter and circumference.
Volume of a sphere
A sphere is the set of all points at the same distance, the radius r, from a centre point. It is the only solid with no edges or flat faces, and it encloses the most volume for a given surface area. Footballs, ball bearings, bubbles and spherical storage tanks are all close to spheres.
Because the radius is cubed, volume grows very quickly with size: a ball with twice the radius holds eight times as much.
Formula
V = 4/3 × π × r³
r = radius (half the diameter)
- If you know the diameter d instead of the radius, use V = π × d³ / 6, or simply halve d first.
- A sphere fills exactly two thirds of the cylinder that tightly encloses it (same radius, height equal to the diameter).
- For the outer skin of the ball, see the surface area calculator; for a hollow shell, subtract the inner sphere’s volume from the outer one.
Worked example: a ball with a 3 cm radius
A solid ball has a radius of 3 cm. If you only know the diameter, halve it first: a 6 cm diameter gives r = 3 cm.
- Cube the radius: 3³ = 27.
- Multiply by 4/3 and by π: V = 4/3 × π × 27 = 36π ≈ 113.097 cm³.
- Convert to litres by dividing by 1,000: 0.1131 L.
V ≈ 113.097 cm³ (0.1131 litres).
Practical details
- Measure across the widest point for the diameter, or wrap a tape around the middle to get the circumference C and use r = C / (2π).
- For a spherical tank, use the inside radius to get the capacity. A part-filled spherical tank is a spherical cap, covered below.
- Multiply the volume by a material’s density to estimate the mass of a solid ball.
Common mistakes
- Entering the diameter where the radius is asked. The answer comes out eight times too large.
- Squaring the radius instead of cubing it. That gives something proportional to area, not volume.
- Mixing units, such as a radius in inches and an answer expected in litres. Pick the unit beside the field and let the calculator convert.
Volume of a cone
A cone has a circular base and tapers smoothly to a single point, the apex. In a right circular cone the apex sits directly above the centre of the base. Funnels, traffic cones, party hats and ice-cream cones follow this shape, and a loose pile of sand or gravel settles into a rough cone.
The volume of a cone is one third of the cylinder with the same base and height. Archimedes’ comparison of cones, spheres and cylinders is one of the oldest results in solid geometry.
Formula
V = 1/3 × π × r² × h
r = base radius, h = perpendicular height (not the slant length)
- The slant length s, measured along the sloping side, is related to the height by s² = r² + h². If you only measured s, find h = √(s² − r²) with the Pythagorean theorem calculator.
- The same one-third rule applies to every pyramid and cone: V = 1/3 × base area × height.
Worked example: radius 3 cm, height 10 cm
A cone has a base radius of 3 cm and a perpendicular height of 10 cm, measured straight from the centre of the base to the tip.
- Base area: π × 3² = 28.274 cm².
- Multiply by the height: 28.274 × 10 = 282.743 cm³.
- Take one third: V = 282.743 ÷ 3 = 94.248 cm³.
V ≈ 94.248 cm³, exactly one third of a cylinder with the same radius and height.
Practical details
- Measure the height straight up from the centre of the base, not along the side.
- A conical pile of material is only an estimate, because real piles are uneven. Measure the diameter of the base and the height at the peak.
- For a cone with its tip cut off, such as a bucket, use the conical frustum calculator.
Common mistakes
- Using the slant length as the height. This overstates the volume.
- Forgetting the factor of one third and calculating the cylinder instead.
- Using the base diameter as the radius.
Volume of a cube
A cube has six identical square faces and twelve equal edges, so one measurement, the edge length a, describes it completely. Dice, sugar cubes, storage cubes and many boxes are cubes.
A cube is the special case of a rectangular box where length, width and height are all the same.
Formula
V = a³
a = edge length (all edges are equal)
- The edge length is multiplied by itself three times, which is why the volume is written with a small 3.
- A cube with a 10 cm edge has a volume of 1,000 cm³, which is exactly 1 litre. A cube with a 1 m edge holds 1 m³, or 1,000 litres.
- Its outer surface is 6a², which the surface area calculator works out for you.
Worked example: a 4 cm edge and a 2 m edge
All twelve edges of a cube are equal, so one measurement is enough.
- Small cube: V = 4³ = 64 cm³.
- Large cube: V = 2³ = 8 m³.
- Convert the large cube to litres: 8 m³ × 1,000 = 8,000 L.
64 cm³ for the small cube; 8 m³ (8,000 litres) for the large one.
Practical details
- Check that all edges really are equal. If they are not, use the rectangular box.
- To compare cube-shaped containers, remember that doubling the edge multiplies the volume by eight.
Common mistakes
- Squaring instead of cubing. a² is an area (the size of one face), not a volume.
- Reading “3” in m³ as a length of three metres. The small 3 only means the unit is cubic.
- Using outside measurements when you want the capacity of a cube-shaped box. Measure the inside.
Volume of a cylinder
A cylinder has two parallel circular ends joined by a curved side. Cans, drums, round water tanks, wells, concrete columns and the inside of a straight pipe are cylinders. This is one of the most common volume calculations, because so many containers are round.
Think of it as a stack of identical circles: the area of one circle times the height of the stack.
Formula
V = π × r² × h
r = radius of the circular base, h = height (length)
- Here h is the height, or the length if the cylinder lies on its side. With the diameter d instead of the radius: V = π × d² × h / 4.
- The orientation does not matter for a completely full cylinder. For a vertical tank filled to a given depth, use the water depth as h.
Worked example: a round water tank
A tank is 1 m across (so r = 0.5 m) and 1.2 m tall. How much water can it hold when full?
- Base area: π × 0.5² = 0.7854 m².
- Multiply by the height: V = 0.7854 × 1.2 = 0.9425 m³.
- Convert: 0.9425 m³ × 1,000 = 942.5 litres, or about 249.0 US gallons.
V ≈ 0.9425 m³ ≈ 942.5 L.
Practical details
- Measure the inside diameter and the inside height to find how much a tank or container can hold.
- Multiply the result in cubic metres by 1,000 for litres, or use the litres and gallons shown under the calculator.
- A horizontal cylinder that is only partly full has a different, more complicated formula; this calculator gives the full volume.
Common mistakes
- Using the diameter as the radius, which makes the answer four times too large.
- Using outside dimensions for a container with thick walls, which overstates the capacity.
- Mixing a radius in centimetres with a height in metres without using the unit menus.
Volume of a rectangular box (rectangular tank)
A rectangular box, also called a cuboid or rectangular prism, has six rectangular faces that meet at right angles. It is a cube whose three dimensions may all be different. Rooms, swimming pools with a flat floor, aquariums, shipping boxes, concrete slabs and raised planting beds all fit this shape.
The volume is the footprint (length times width) multiplied by the height or depth.
Formula
V = l × w × h
l = length, w = width, h = height
- Use the same unit for all three lengths, or let the unit menus convert for you.
- Dividing the volume in cm³ by 1,000 gives litres. A 60 cm × 30 cm × 30 cm aquarium is 54,000 cm³, or 54 litres.
- If a pool or trench has a floor that slopes evenly, the average depth (shallow end plus deep end, divided by two) can be used as h.
Worked example: a concrete slab
A slab is 5 m long, 3 m wide and 100 mm (0.1 m) thick. Convert every length to the same unit before multiplying.
- Convert the thickness: 100 mm = 0.1 m.
- Multiply: V = 5 × 3 × 0.1 = 1.50 m³.
- That is 1,500 litres, or about 52.97 cubic feet.
V = 1.50 m³. Check with your supplier about extra allowance for waste and uneven ground.
Practical details
- For a slab, footing or paving base, enter the thickness in millimetres and the length and width in metres, each with its own unit menu.
- For a tank, use the water depth as h to get the volume of water, and the full inside height to get its capacity.
- Suppliers often advise allowing a little extra for waste and uneven ground. Check with yours.
Common mistakes
- Forgetting to convert a thickness given in millimetres or inches.
- Using outside dimensions for a container or tank.
- Using the maximum depth of a pool with a sloping floor instead of the average depth.
Volume of a capsule
A capsule is a cylinder with a hemisphere on each end. Medicine capsules are the familiar example, and some horizontal tanks and pressure vessels have a straight middle section and rounded ends of the same radius.
Its volume is the cylinder part plus the volume of two hemispheres, which together make one full sphere.
Formula
V = π × r² × h + 4/3 × π × r³
r = radius of the hemispherical ends, h = length of the straight cylindrical middle only
- Written together: V = π × r² × (h + 4r/3).
- The overall length L from tip to tip is h + 2r. If you measured the overall length, subtract 2r to get h.
Worked example: end radius 2 cm, straight middle 6 cm
A capsule is a cylinder with a hemisphere on each end. Here h is the straight middle only, so the overall length is 6 + 2 × 2 = 10 cm.
- Cylinder part: π × 2² × 6 = 75.398 cm³.
- Two hemispheres make one sphere: 4/3 × π × 2³ = 33.510 cm³.
- Add them: V = 75.398 + 33.510 = 108.909 cm³.
V ≈ 108.909 cm³.
Practical details
- Measure the overall length and the diameter, then work out h = L − 2r before entering it.
- The formula assumes hemispherical ends. Tanks with flatter dished or elliptical ends hold less than this formula suggests.
Common mistakes
- Entering the overall length as h. This counts the two rounded ends twice.
- Using the diameter as the radius.
- Applying the capsule to a tank with flat or dished ends.
Volume of a spherical cap
A spherical cap is the piece of a sphere cut off by a flat plane: a dome sitting on a circular base. Bowls, domes, lenses and the liquid in a spherical tank that is less than full are all spherical caps.
Three lengths describe a cap: the radius R of the sphere it was cut from, the height h of the cap, and the radius a of its circular base. Any two of them fix the third, so the calculator asks for exactly two.
Formula
V = 1/3 × π × h² × (3R − h)
R = sphere radius, h = cap height, a = cap base radius, with a² = h × (2R − h)
- With the base radius a instead of the sphere radius R: V = 1/6 × π × h × (3a² + h²).
- The three lengths are related by a² = h × (2R − h), and R = (a² + h²) / (2h).
- When h = R the cap is a hemisphere, and when h = 2R it is the whole sphere.
Worked example: sphere radius 5 cm, cap height 2 cm
A dome is cut from a sphere of radius R = 5 cm and stands h = 2 cm tall. Its base radius follows from a² = h × (2R − h) = 2 × 8 = 16, so a = 4 cm.
- Compute 3R − h = 15 − 2 = 13.
- Multiply: π × h² × 13 = π × 4 × 13 = 163.363.
- Divide by 3: V = 163.363 ÷ 3 = 54.454 cm³.
V ≈ 54.454 cm³. Entering R = 5 and a = 4 instead gives the same answer.
Practical details
- For a spherical tank filled to a depth h, measured from the bottom, the liquid forms a cap of height h, so enter the tank’s inside radius R and the liquid depth.
- If you enter R and a, the calculator returns the smaller cap (less than a hemisphere). To get the larger cap, enter R and h.
- Measure h as the straight height from the flat base to the top of the dome.
Common mistakes
- Entering all three values or only one. Leave exactly one field blank.
- A cap height larger than the sphere’s diameter, or a base radius larger than the sphere radius. Neither is possible.
- Using the length along the curved surface instead of the straight height.
Volume of a conical frustum
A conical frustum is a cone with its tip sliced off by a plane parallel to the base. It has a larger circle at the bottom, a smaller circle at the top and sloping sides. Buckets, flower pots, paper cups, lampshades and many hoppers are frustums.
Its volume can be found as the volume of the full cone minus the small cone that was removed, which simplifies to a single formula.
Formula
V = 1/3 × π × h × (r₁² + r₁ × r₂ + r₂²)
r₁ = bottom radius, r₂ = top radius, h = height between the two circles
- r₁ and r₂ are the radii of the two circles and h is the perpendicular height between them, not the slanted side.
- If r₁ = r₂ the formula becomes π × r² × h, the cylinder. As r₂ shrinks towards zero it approaches the cone, which has its own calculator.
- The slant length along the side is √(h² + (r₁ − r₂)²).
Worked example: bottom radius 4 cm, top radius 2 cm, height 10 cm
A tapered cup or flower pot is a cone with its tip cut off parallel to the base.
- Squares and product: r₁² + r₁r₂ + r₂² = 16 + 8 + 4 = 28.
- Multiply by π × h: π × 10 × 28 = 879.646.
- Divide by 3: V = 879.646 ÷ 3 = 293.215 cm³.
V ≈ 293.215 cm³ (0.2932 litres).
Practical details
- For a bucket or pot, measure the inside diameters at the rim and the base and the inside depth to get its capacity.
- The order of the two radii does not matter, because the formula is symmetrical in r₁ and r₂.
Common mistakes
- Using the slant length as the height.
- Entering diameters instead of radii.
- Using outside dimensions for a container, which ignores the wall thickness.
Volume of an ellipsoid
An ellipsoid is a stretched or squashed sphere. It has three semi-axes a, b and c, each half the full width, height or depth. If all three are equal it is a sphere; if two are equal it is a spheroid, like a rugby ball (elongated) or a flattened planet.
Rugby balls, oval tanks and many fruits are well approximated by ellipsoids. Eggs are only roughly ellipsoidal, so treat their result as an estimate.
Formula
V = 4/3 × π × a × b × c
a, b, c = the three semi-axes (half of the full width, height and depth)
- Each semi-axis is half of the full width, height or depth, and the three are simply multiplied together.
- For a spheroid with two equal semi-axes a and one different semi-axis c, V = 4/3 × π × a² × c.
- Setting a = b = c = r gives the sphere formula 4/3 × π × r³.
Worked example: semi-axes 4 cm, 3 cm and 2 cm
The semi-axes are half of the full width, height and depth, so this solid measures 8 cm × 6 cm × 4 cm at its widest points.
- Multiply the semi-axes: 4 × 3 × 2 = 24.
- Apply 4/3 × π: V = 4/3 × π × 24 = 32π ≈ 100.531 cm³.
V ≈ 100.531 cm³. If all three semi-axes were equal the formula would reduce to the sphere formula.
Practical details
- Measure the full length, width and height, then halve each one before entering them as semi-axes.
- The order of a, b and c does not matter, since the three are simply multiplied together.
Common mistakes
- Entering full lengths instead of semi-axes. The result is eight times too large.
- Using it for shapes that are not symmetrical, such as an egg with a pointed end.
Volume of a square pyramid
A square pyramid has a square base and four triangular faces that meet at the apex above the centre of the base. The same shape appears in monuments, roof hips, tents, paperweights and some hoppers.
Like a cone, a pyramid holds one third of the prism with the same base and height.
Formula
V = 1/3 × a² × h
a = base edge, h = perpendicular height from the base to the apex
- The height of each triangular face (the slant height) is √(h² + (a/2)²), which is used for surface area rather than volume.
- For a pyramid whose base is a rectangle or another shape, V = 1/3 × base area × height. For a rectangular base, enter the length, width and height in the rectangular box calculator and divide the result by three.
Worked example: base edge 4 cm, height 10 cm
The height is the perpendicular distance from the base to the apex, not the length of a sloping face.
- Base area: 4² = 16 cm².
- Multiply by the height and divide by 3: V = 16 × 10 ÷ 3 = 53.333 cm³.
V ≈ 53.333 cm³, one third of a box with the same base and height.
Practical details
- Measure the height straight up from the centre of the base, not up the sloping face.
- For a roof or hopper, use the area calculator for an irregular base and divide base area times height by three.
Common mistakes
- Using the slant height of a face instead of the vertical height.
- Forgetting the one-third factor.
- Using a rectangular base with a single edge value. This calculator assumes a square base.
Volume of a tube (hollow cylinder)
A tube, or hollow cylinder, is a cylinder with a cylindrical hole through its length. Pipes, rings, bushings, hollow columns and drinking straws are tubes. Here the volume means the volume of the wall material, the metal or plastic itself, not the empty space inside.
It equals the volume of the outer cylinder minus the volume of the hole.
Formula
V = π × h × (R² − r²)
R = outer radius, r = inner radius, h = length. This is the volume of the wall material, not the hollow space.
- The wall thickness is t = R − r, and the formula can also be written V = π × h × t × (R + r).
- To find the mass of a pipe section, multiply the volume by the density of the material.
Worked example: outer radius 5 cm, inner radius 4 cm, length 10 cm
This gives the volume of the wall material of a pipe or ring, not the empty space inside it.
- Subtract the squared radii: R² − r² = 25 − 16 = 9.
- Multiply by π × h: V = π × 10 × 9 = 90π ≈ 282.743 cm³.
- For the empty inside of the same pipe, use the cylinder calculator with r = 4 cm and h = 10 cm: 502.655 cm³.
Wall volume V ≈ 282.743 cm³.
Practical details
- For the capacity of the pipe, meaning the liquid it holds, use the cylinder calculator with the inner radius instead.
- Nominal pipe sizes are often not the same as the actual diameters, so measure the real inner and outer diameters.
Common mistakes
- Entering an inner radius equal to or larger than the outer radius. The calculator rejects it.
- Using the tube calculator when you actually want the capacity of the pipe.
- Entering diameters in the radius fields.
Handy relationships
- A cone or pyramid holds exactly one third of the cylinder or box with the same base and height.
- A sphere holds two thirds of the cylinder that just encloses it (same radius, height equal to the diameter).
- Doubling every dimension multiplies the volume by 8, because volume scales with the cube of length.
- For any pyramid or cone, V = ⅓ × base area × height, whatever the shape of the base.
Volume unit conversion table
Read across a row: “1 cubic foot equals …”. Factors come from the exact definitions of the inch (25.4 mm), the US gallon (231 cubic inches) and the Imperial gallon (4.54609 litres). For other kinds of conversion use the unit conversion calculator.
| 1 unit = | cm³ | L | m³ | in³ | ft³ | US gal | UK gal |
|---|---|---|---|---|---|---|---|
| 1 mm³ | 0.001 | 10⁻⁶ | 10⁻⁹ | 6.1024 × 10⁻⁵ | 3.5315 × 10⁻⁸ | 2.6417 × 10⁻⁷ | 2.1997 × 10⁻⁷ |
| 1 cm³ | 1 | 0.001 | 10⁻⁶ | 0.061024 | 3.5315 × 10⁻⁵ | 2.6417 × 10⁻⁴ | 2.1997 × 10⁻⁴ |
| 1 L | 1,000 | 1 | 0.001 | 61.024 | 0.035315 | 0.26417 | 0.21997 |
| 1 m³ | 1,000,000 | 1,000 | 1 | 61,024 | 35.315 | 264.17 | 219.97 |
| 1 in³ | 16.387 | 0.016387 | 1.6387 × 10⁻⁵ | 1 | 5.787 × 10⁻⁴ | 0.004329 | 0.0036047 |
| 1 ft³ | 28,317 | 28.317 | 0.028317 | 1,728 | 1 | 7.4805 | 6.2288 |
| 1 yd³ | 764,550 | 764.55 | 0.76455 | 46,656 | 27 | 201.97 | 168.18 |
| 1 US gal | 3,785.4 | 3.7854 | 0.0037854 | 231 | 0.13368 | 1 | 0.83267 |
| 1 UK gal | 4,546.1 | 4.5461 | 0.0045461 | 277.42 | 0.16054 | 1.2009 | 1 |
1 mL equals 1 cm³. Values are shown to five significant figures.
Litres, cubic metres, gallons and other volume units
- Litre (L) and millilitre (mL)
- A litre is a thousandth of a cubic metre, so 1 L = 1,000 cm³ and 1 mL = 1 cm³. It is the everyday unit for liquids and for the capacity of tanks, bottles and containers.
- Cubic metre (m³)
- The SI unit of volume. 1 m³ = 1,000 L. It is the usual unit for concrete, soil, gravel, rooms and large tanks.
- US gallon (gal)
- Defined as 231 cubic inches, which is exactly 3.785411784 litres. One cubic metre is about 264.172 US gallons.
- Imperial (UK) gallon (gal)
- Defined as exactly 4.54609 litres, about 20% larger than the US gallon. Always check which gallon a figure uses.
- Cubic foot (ft³) and cubic yard (yd³)
- 1 ft³ = 28.3168 L (about 7.4805 US gallons). 1 yd³ = 27 ft³ = 0.764555 m³; US concrete and soil are often sold by the cubic yard.
- Cubic inch (in³)
- 1 in³ = 16.387064 cm³ exactly, from 1 in = 2.54 cm.
Volume is measured in cubic units, so doubling every dimension multiplies the volume by eight. For capacity, 1 cubic metre equals 1,000 litres and 1 millilitre equals 1 cubic centimetre. US and UK gallons differ (3.785 L and 4.546 L), so both are shown.
Which shape should you choose?
Match the real object to the closest solid, then use the calculator for that shape. Oddly shaped containers are best treated as an estimate. A cone’s height and slant length are linked by the Pythagorean theorem, so you can recover the height from a measured slant length and the radius.
Round water tank, drum, can, well or column
Use inside dimensions for capacity.
Ball, bubble or spherical tank
Halve the diameter to get the radius.
Funnel, traffic cone or conical pile
Height is vertical, not along the slope.
Cube-shaped box or block
All edges must be equal.
Room, pool, aquarium, slab or planter bed
For a sloping floor use the average depth.
Pill, or tank with hemispherical ends
Enter the straight middle length only.
Dome, bowl or part-filled spherical tank
Enter any two of R, h and a.
Bucket, flower pot or lampshade
Measure both rim and base radius.
Rugby ball or oval tank
Enter half of each full dimension.
Pyramid, roof hip or square hopper
Use the vertical height.
Pipe wall, ring or hollow column
This is the material, not the hollow space.
Practical uses
- Working out how much concrete, soil or gravel to order.
- Sizing a water tank, bucket or planter.
- Checking packaging and container volumes.
- Converting a volume in cubic feet, cubic metres or litres into gallons.
Assumptions and limitations
- Ideal geometric shapes only; real objects have thickness, curvature, slopes and tolerances.
- Hollow objects need their wall thickness handled separately; the tube shape gives the volume of the wall material, and a cylinder with the inner radius gives the space inside.
- Partly filled horizontal cylindrical tanks are not covered. A part-filled spherical tank can be treated as a spherical cap.
- Results are shown to 10 significant figures, but measurement error in your inputs is usually far larger than that.
Results are mathematical volumes of ideal shapes. For purchases, structural work or anything safety-related, measure on site and confirm quantities with your supplier or a qualified professional.
Sources and further reading
Formulas and unit definitions can be checked against these references.