Quick answer: volume is the amount of three-dimensional space an object occupies, measured in cubic units (cm³, ft³, m³) or liquid units (liters, gallons). For a box it is simply length × width × height; curved and pointed shapes use their own formulas — each has a dedicated calculator, and all of them are listed in the table below.
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Volume Calculator
Enter length, width and height — in any units — and get the volume instantly, with the exact formula and working shown. Need a cylinder, sphere or cone? Every shape has its own dedicated calculator below.
- ✓ Mix inches, feet, cm & meters
- ✓ Formula shown with your numbers
- ✓ Results in ft³, m³, liters & gallons
Formula with your numbers
V = π r² h
Volume
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Enter the dimensions above — the volume updates instantly.
- 79Calculators & guides
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Explore the full suite
Every volume calculator, organized by what you're doing
The universal tool above covers pure geometry. When your problem has real-world context — gallons in a pool, yards of soil, liters in a surfboard — a purpose-built calculator gives you the right units and guidance for that exact job.
- Shape Volume Calculators
Cylinder, sphere, cone, pyramid, prism and a dozen more — with formulas, labeled diagrams and worked examples for each.
17 calculators - Tank & Liquid Volume
Tanks with fill-level mode, pools, pipes, aquariums, ponds and wells — gallons-first results for real containers.
11 calculators - Construction & Landscaping
Concrete, soil, gravel, sand and asphalt in cubic yards — with bag counts, density tables and ordering tips.
10 calculators - Medical & Scientific
Prostate, tidal, bladder and blood volume plus lab tools — built on cited clinical formulas with references.
13 calculators - Specialty & Everyday
Surfboard liters, subwoofer boxes, freight CBM, dimensional weight and volume-to-weight conversions.
6 calculators - Formulas, Units & Guides
Every volume formula on one page, cubic and liquid units explained, and how-to guides for any measurement.
10 guides
How it works
Four steps to an answer you can verify
- Measure your object
Length, width and height for the tool above — or jump to the dedicated calculator if your object is round, tapered or hollow.
- Enter each dimension
Every field has its own unit selector. A box measured 18 inches by 2 feet by 30 cm is a perfectly valid input.
- Read the result instantly
It updates as you type. Switch the output to cubic feet, cubic meters, liters or gallons without re-entering anything.
- Check the working
The formula bar shows your numbers substituted into the equation — verify it with a pencil, or copy it into homework or a quote.
One habit worth keeping: if your shape has a diameter written on it (pipes and tanks usually do), halve it before entering the radius. Entering a diameter where a radius belongs inflates the result by 4× — the single most common volume-calculation mistake we see.
Why CalculateVolume.org
Built to be checked, not just believed
- Formula-transparent
Every result comes with the equation and your numbers substituted into it. Nothing here is a black box.
- Tested against worked examples
Every calculator must reproduce hand-verified answers before it ships — a cylinder with r = 3, h = 5 returns 141.372, every time.
- Unit-mixing built in
Real measurements come in mixed units. Enter each dimension in whatever unit it was measured — conversion is automatic.
- Private by design
All math runs in your browser. The numbers you enter never leave your device — see our privacy policy.
- Fast on any device
Hand-written HTML, CSS and JavaScript with no frameworks — pages load fast even on a weak phone signal at a job site.
- Cited where it counts
Engineering and medical calculators name their published formulas and link the sources — read our accuracy policy.
Volume formulas for every common shape
The calculator above handles anything box-shaped. For every other shape, use its formula below — each links to a dedicated calculator with a labeled diagram, worked examples and its own reference tables.
| Shape | Formula | Dimensions needed |
|---|---|---|
| Cube | V = a³ | Edge length |
| Box (rectangular prism) | V = l × w × h | Length, width, height |
| Cylinder | V = π r² h | Radius, height |
| Sphere | V = (4/3) π r³ | Radius |
| Hemisphere | V = (2/3) π r³ | Radius |
| Cone | V = (1/3) π r² h | Base radius, height |
| Truncated cone (frustum) | V = (1/3) π h (r₁² + r₁r₂ + r₂²) | Both radii, height |
| Square pyramid | V = (1/3) a² h | Base edge, height |
| Rectangular pyramid | V = (1/3) l w h | Base length, width, height |
| Triangular prism | V = ½ b h l | Triangle base & height, prism length |
| Capsule | V = π r² a + (4/3) π r³ | Radius, cylinder length |
| Ellipsoid | V = (4/3) π a b c | Three semi-axes |
| Tube (hollow cylinder) | V = π (R² − r²) h | Outer & inner radius, length |
All 17 dedicated shape pages — each with its own worked examples, reference tables and FAQs — are indexed on the shape volume calculators hub.
Worked examples with real numbers
A cylindrical water tank
A vertical tank is 4 ft across (so r = 2 ft) and 5 ft tall. Volume = π × 2² × 5 = 62.83 ft³. At 7.4805 gallons per cubic foot, that tank holds about 470 US gallons. For fill levels and horizontal tanks, the dedicated tank volume calculator handles partially filled cylinders too.
A concrete patio slab
A 10 ft × 12 ft slab poured 4 inches thick is a box: 10 × 12 × 0.333 = 40 ft³, which is 40 ÷ 27 ≈ 1.48 cubic yards of concrete. Ordering-ready numbers, bag counts and waste margins live in the concrete volume calculator.
A homework sphere
A sphere with radius 3 cm: V = (4/3) × π × 3³ = (4/3) × π × 27 = 113.1 cm³. Notice the radius is cubed — doubling a sphere's radius makes its volume eight times larger, which is why a slightly bigger balloon holds so much more air.
Cubic units and liquid units, briefly
Volume answers come in two families. Cubic units (in³, ft³, yd³, cm³, m³) describe space directly and are what geometry formulas produce. Liquid units (mL, L, gallons) describe the same space in container terms. The bridges between them are worth memorizing:
| This much… | …equals this |
|---|---|
| 1 cubic foot | 7.4805 US gal · 28.317 L · 1,728 in³ |
| 1 cubic meter | 1,000 L · 264.17 US gal · 35.315 ft³ |
| 1 cubic yard | 27 ft³ · 201.97 US gal · 764.55 L |
| 1 US gallon | 231 in³ · 3.7854 L · 0.1337 ft³ |
| 1 liter | 1,000 cm³ · 0.2642 US gal · 61.024 in³ |
Note that a UK (imperial) gallon is 4.546 liters — about 20% larger than a US gallon. The result menu above offers both, and the volume conversion calculator converts between all ten units directly.
Frequently asked questions
How do you calculate volume?
Volume measures the three-dimensional space an object occupies. For box-like shapes, multiply length × width × height. Rounded and pointed shapes each have their own formula — a cylinder is π r² h, a sphere is (4/3) π r³, and a cone is one-third of the matching cylinder at (1/3) π r² h. Measure every dimension in the same unit, apply the formula, and the answer comes out in that unit cubed.
What is the formula for volume?
There is no single volume formula — it depends on the shape. The most common are: cube V = a³, box V = l × w × h, cylinder V = π r² h, sphere V = (4/3) π r³, cone V = (1/3) π r² h, and pyramid V = (1/3) × base area × height. For any prism, multiply the cross-section area by the length.
How do I convert a volume result to gallons or liters?
Compute the volume in cubic units first, then convert: 1 cubic foot = 7.4805 US gallons = 28.317 liters, and 1 cubic meter = 264.17 US gallons = 1,000 liters. This calculator does the conversion for you — pick gallons or liters from the result unit menu.
Can I mix units, like feet and inches, in one calculation?
Yes. Each dimension in this calculator has its own unit selector, so you can enter a pipe's diameter in inches and its length in feet. Everything is converted internally before the formula is applied, which removes the most common source of volume errors — mismatched units.
What is the difference between volume and capacity?
Volume is the space an object occupies; capacity is how much a container can hold. A tank with thick walls has an external volume larger than its internal capacity. For solid objects the two are effectively the same number, but for containers always measure the inside dimensions when you care about what fits.
How do I find the volume of an irregular object?
Use water displacement: submerge the object in a graduated container and measure how much the water level rises — that rise equals the object's volume. For irregular spaces like a sloped yard or kidney-shaped pool, split the space into simple shapes, calculate each one, and add the results.
Need a calculator for a specific job?
Tanks, pools, concrete, freight, surfboards, clinical formulas — there's a purpose-built volume calculator for each, with the right units and reference tables.
Browse all calculators