About CalculateCubicFeet
CalculateCubicFeet is a free, ad-supported reference for anything that touches cubic feet — from measuring a moving truck to sizing a sauna heater to ordering 14 cubic yards of concrete. Every calculator on the site runs in your browser, every formula is documented, and every result is checked against published reference values.
Why we built it
Cubic feet is a deceptively tricky unit. The math is simple, but the inputs come in inches, yards, centimeters, and meters. Materials are sold by the cubic yard, the cubic meter, the gallon, and the bag. Appliances are rated in cubic feet but you only ever see the outside. The result: a lot of people guess, round wrong, and either overspend on materials or come up short halfway through a project.
We started CalculateCubicFeet because the existing tools mostly handled one shape, one unit, or one use case at a time. We wanted a single site where you could plug in mixed units, pick any common shape, see a 3D preview of what you measured, and get a result you can trust — with the formula and conversion factor visible right there on the page.
What you can do here
- Calculate cubic feet for any shape. Rectangles, cylinders, spheres, cones, prisms, pyramids, capsules, and irregular composite shapes. Each calculator accepts mixed units and shows the formula.
- Convert in any direction. Cubic feet to cubic yards, cubic meters, gallons, liters, board feet, BTU, square feet (with depth), pounds, tons. See our full list of converters.
- Solve real-world problems. Concrete bag counts, mulch and soil orders, moving truck sizing, refrigerator capacity, sauna heater wattage, swimming pool gallons, subwoofer enclosure volumes, raised garden beds, and more. Browse all use-case pages.
- Learn the formulas. Our how-to guide, formulas reference, and common mistakes page cover the math from first principles.
Our accuracy commitment
Every calculator is unit-tested. We use exact conversion factors where possible (1 ft = 0.3048 m exactly, 1 US gallon = 231 in³ exactly, 1 cubic yard = 27 cubic feet exactly) and document any material density that varies with moisture or compaction.
Specific commitments:
- Length and volume conversions are accurate to at least five significant figures.
- π is computed at full double precision, never approximated as 3.14 or 22/7.
- Material weight factors are sourced from US DOT, USGS, USDA, NRCS, and FAO published densities. Where literature ranges exist, we use the midpoint of the range and note the variation.
- Concrete bag yields (80 lb = 0.6 ft³, 60 lb = 0.45 ft³, 40 lb = 0.30 ft³) match the labels on Quikrete, Sakrete, and major US concrete brands.
- Truck capacity numbers (10 ft = 380 ft³, 15 ft = 760 ft³, etc.) are taken directly from U-Haul, Penske, and Budget published specs and are kept current.
How the site works
CalculateCubicFeet is built as a static site. There is no server-side calculation, no database, and no account system. Your measurements are entered in your browser, calculated in your browser, and never sent to us. We do not collect your inputs or your results.
We use privacy-respecting analytics to track which pages are popular and which calculators get used the most. That data is aggregated and anonymous. We do not track individuals. Read more in our privacy policy.
Who is behind this
The site is run by a small team with backgrounds in civil engineering, software development, and technical writing. We have spent enough time on construction sites, in moving trucks, and in HVAC supply houses to know which questions actually matter — and which conversion factors people need to look up over and over again.
We are happy to take corrections, requests for new calculators, and feedback on the formulas. Reach out via the contact page.
Sources and references
- NIST Special Publication 811, Guide for the Use of the International System of Units (SI)
- US Code of Federal Regulations, 49 CFR §171.7 (units of measurement for shipping)
- US Geological Survey, Densities of Common Materials
- USDA Natural Resources Conservation Service, Soil Survey Field and Laboratory Methods Manual
- FAO Forestry Department, Wood Density Database
- Manufacturer published spec sheets for Quikrete, Sakrete, U-Haul, Penske, and Budget
What makes us different
Most cubic feet calculators give you a number and stop there. We try to answer the next question too: how many bags of concrete is that, which truck size do I need, how much will it weigh, and what wattage of heater can warm that volume? Every page links the formula, the conversion, the practical outcome, and the related calculator so you only have to look in one place.