# Gallons to Cubic Feet Converter URL: https://speedycalculator.com/calculators/conversion/gallons-to-cubic-feet/ Last updated: 2026-10-25 > Convert US gallons (US gal) to cubic feet (ft³): 1 US gallon = 0.13368056 ft³, so multiply by 0.13368056 or divide by 7.4805195. Both fields are editable, so you can also type in cubic feet and get US gallons back. ## Inputs - US gallons (US gal) ## Results - Cubic feet ## Formula ``` 1 US gal = 0.13368056 ft³ 1 ft³ = 7.4805195 US gal ft³ = US gal × 0.13368056 ``` ## Explanation Divide U.S. gallons by 7.48052 to get cubic feet. Water heaters, fish tanks and fuel tanks rated in gallons convert to space requirements this way. ### How to use the Gallons to Cubic Feet Converter - Type the number of US gallons into the **US gallons** field. Decimals such as 500 are fine. - Read the answer in **Cubic feet** – it updates as you type, with no button to press. - To convert the other way, type into **Cubic feet** and the US gallons are recalculated. - Press **Copy results** to copy both values with the page title, or **Copy link** to share this exact conversion. This page converts only US gal ⇄ ft³. Need a different unit? Use the general volume converter, where you can choose any “from” and “to” unit. ### How it works Both units measure volume, so they are always in the same ratio: one US gallon equals 0.13368056 cubic feet. The calculator multiplies the number of US gallons you type by 0.13368056 to give cubic feet, and when you type into the cubic feet field it divides by the same factor to give US gallons. Because the ratio never changes, doubling the US gallons always doubles the cubic feet. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation). ### How to convert US gallons to cubic feet - Write down the value in US gallons, for example **1,000 US gal**. - Multiply by the conversion factor 0.13368056 (because 1 US gallon = 0.13368056 ft³). - 1,000 × 0.13368056 = **133.68056 ft³**. - To go back from cubic feet to US gallons, divide by 0.13368056 – or multiply by 7.4805195. ### US gal to ft³ conversion table US gallonsCubic feetCubic feetUS gallons1 US gal0.13368056 ft³1 ft³7.4805195 US gal5 US gal0.66840278 ft³2 ft³14.961039 US gal10 US gal1.3368056 ft³5 ft³37.402597 US gal50 US gal6.6840278 ft³10 ft³74.805195 US gal100 US gal13.368056 ft³20 ft³149.61039 US gal500 US gal66.840278 ft³50 ft³374.02597 US gal1,000 US gal133.68056 ft³100 ft³748.05195 US gal10,000 US gal1,336.8056 ft³1,000 ft³7,480.5195 US gal ### What is a US gallon? The U.S. liquid gallon is exactly 231 cubic inches, about 3.785 litres. It is used for fuel, milk, water and paint in the United States. ### What is a cubic foot? A cubic foot is a cube 1 ft on each side, about 28.32 litres or 7.48 U.S. gallons. Refrigerators, moving trucks, gas meters and lumber are measured in cubic feet in the U.S. ### Quick mental conversion For a fast estimate, multiply US gallons by about **0.13** to get cubic feet; the error is about 2.8%. Use the calculator above when you need the exact figure. ### Common mistakes to avoid Mixing u.s. and uk gallons, pints and fluid ounces, assuming a cup is always 250 ml, and treating volume and weight as interchangeable for anything except water. ## Worked example Inputs — US gallons: 1,000 US gal. Results — **Cubic feet = 133.68055556 ft³**. ## FAQ **How many cubic feet is 1,000 gallons?** About 133.68 ft³. **How many gallons in a cubic foot?** About 7.48. **How many cubic feet are in one US gallon?** 1 US gal = 0.13368056 ft³. **How many US gallons are in one cubic foot?** 1 ft³ = 7.4805195 US gal. **How do I convert US gallons to cubic feet?** Multiply the number of US gallons by 0.13368056. For example, 1,000 US gal × 0.13368056 = 133.68056 ft³. **How do I convert cubic feet back to US gallons?** Divide by 0.13368056 (or multiply by 7.4805195), or simply type the value into the cubic feet field above. **What is 10 US gal in cubic feet?** 10 US gal = 1.3368056 ft³. **What is 100 US gal in cubic feet?** 100 US gal = 13.368056 ft³. **Is this conversion exact?** Yes. The factor comes from the official definitions of both units (NIST and the SI), so the only difference you may see is rounding in the last displayed digit. **Can I convert to other units on this page?** This page converts only between US gallons and cubic feet. To pick any volume unit, use the general volume converter linked under Related calculators. **What formula does the Gallons to Cubic Feet Converter use?** 1 US gal = 0.13368056 ft³. ## Sources - [NIST Special Publication 811 – Guide for the Use of the International System of Units](https://www.nist.gov/pml/special-publication-811) - [NIST Handbook 44 Appendix C – General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)