Volume Calculator — Cubic Feet, Gallons, Tanks & Materials
Calculate shapes, tanks, pools, materials, missing dimensions, or convert cubic feet, cubic yards, gallons, liters, and cubic meters.
Volume and surface area of a solid
Choose one of eleven solids, enter dimensions in any supported unit, and convert volume without repeating the calculation.
Tank capacity and current liquid volume
Use inside dimensions, then set fill level. Horizontal cylinders use circular-segment geometry, so half the depth is exactly half the capacity.
Pool, pond, and aquarium water volume
Average shallow and deep ends, calculate capacity, and estimate fill time and water cost. Dimensions should describe the inside water space.
Concrete, soil, mulch, or fill project
Add rectangular sections, repeat identical sections with quantity, subtract voids, then include waste, package rounding, and estimated cost.
Find a missing dimension from target volume
Choose what is unknown, enter a target volume and known dimensions, then get the exact required length, height, radius, diameter, or depth.
Solid diagram
Calculation
Volume details
Volume unit converter
Convert an existing volume between cubic feet, cubic yards, gallons, liters, and metric units without entering dimensions.
1 ft³ × 7.48051948 = 7.48052 US gal
| Starting volume | US gallons | Liters | Cubic feet | Cubic meters |
|---|---|---|---|---|
| 1 cubic foot | 7.48052 gal | 28.3168 L | 1 ft³ | 0.0283168 m³ |
| 1 cubic yard | 201.974 gal | 764.555 L | 27 ft³ | 0.764555 m³ |
| 1 cubic meter | 264.172 gal | 1,000 L | 35.3147 ft³ | 1 m³ |
| 1 US liquid gallon | 1 gal | 3.78541 L | 0.133681 ft³ | 0.00378541 m³ |
US liquid gallons and Imperial gallons are different units. The converter labels both explicitly; it does not use the US dry gallon.
Cubic feet and cubic yards calculator
Calculate a solid once and read it in cubic feet, cubic yards, cubic meters, liters, US gallons, or other practical units. Surface area is included where the selected solid has a closed-surface formula.
Tank volume and liquid level
Rectangular and vertical cylindrical tanks scale linearly with liquid height. A horizontal cylinder does not, so this calculator applies the circular-segment formula to the entered fill depth.
Pool, pond, and aquarium gallons
Use average depth for a sloped floor, then estimate water capacity, current fill, refill time, and water cost. Rectangular, round, and oval footprints are supported.
Concrete and landscape material volume
Build a project from several rectangular sections, subtract voids, add waste, and round up to full bags, packages, or truck quantities using the supplier's stated package volume.
Frequently asked questions
How do I calculate cubic feet?
Convert every dimension to feet, then multiply length × width × height for a rectangular space. Other solids use their own formula, such as πr²h for a cylinder.
How many cubic feet are in a cubic yard?
One cubic yard equals exactly 27 cubic feet. Divide cubic feet by 27 to get cubic yards, or multiply cubic yards by 27 to get cubic feet.
How do I find pool gallons with a sloped bottom?
Use the average of shallow and deep water depths, multiply by the pool footprint, then convert cubic feet to US gallons. Irregular curves may require measured sections.
Why is a horizontal tank not linear by fill height?
The tank is narrower near the top and bottom than at the center. The calculator uses a circular segment, so liquid volume follows the actual cross-section.
How much waste should I add for concrete or mulch?
Waste depends on excavation, compaction, spillage, shape, and supplier rules. Use the project allowance as a planning estimate and confirm the order with the supplier or contractor.
Measurement notes
Results are mathematical estimates. Use inside dimensions for capacity, keep all measurements consistent, and confirm site conditions, displacement, compaction, package yield, and local construction requirements before ordering or filling.
