US gallons to Cubic meters Converter
Convert US gallons (gal) to Cubic meters (m³) instantly, or use the conversion table below to look up common values.
US gallons to Cubic meters conversion table
| US gallons (gal) | Cubic meters (m³) |
|---|---|
| 1 | 0.003785 |
| 2 | 0.007571 |
| 3 | 0.011356 |
| 4 | 0.015142 |
| 5 | 0.018927 |
| 10 | 0.037854 |
| 25 | 0.094635 |
| 50 | 0.189271 |
| 100 | 0.378541 |
How to convert US gallons to Cubic meters
1 gal equals 0.003785 m³. Use the converter above for any value, or read the table for common conversions.
m³ = gal × 0.0037854117839999997 · gal = m³ × 264.17205235814845Multiply a us gallons figure by 0.003785 to get cubic meters, or divide it by 264.172052 to go the other way.
Worked examples
- 1 gal= 0.003785 m³
- 2 gal= 0.007571 m³
- 5 gal= 0.018927 m³
- 10 gal= 0.037854 m³
- 20 gal= 0.075708 m³
What these units are
US gallons (gal). A US gallon is 3.785411784 liters, defined as 231 cubic inches. It is the standard liquid and fuel unit in the United States, and is about 20% smaller than an imperial gallon.
Cubic meters (m³). A cubic meter is 1,000 liters, and the volume of a cube one meter on each side. It is used for bulk water, concrete and sand, and for shipping volume.
US and imperial units are kept separate because they are genuinely different sizes. Confirm which system a source means before trusting a converted figure.
Converting US gallons to Cubic meters in practice
Working in us gallons
A US gallon is exactly 3.785411784 liters, or 231 cubic inches, and it divides into four quarts, eight pints or 128 US fluid ounces. It is a defined liquid volume and not a unit of mass.
Fuel at filling stations, paint, milk, water and agricultural sprays are sold by the US gallon in the United States and in some export markets. Larger tanks and drums are also rated in gallons.
The site uses the US gallon of exactly 3.785411784 liters; the imperial gallon is exactly 4.54609 liters and is roughly a fifth larger. Display rounding can move the final digit of a gallon to liter conversion taken both ways.
The frequent mistake is applying the imperial gallon to a US figure or the reverse, which misstates fuel or tank volume by around a fifth. A gallon also measures volume, while a gallon of a specific liquid has a mass.
The US gallon belongs with quarts, pints and fluid ounces, while the imperial gallon and the liter sit on other scales. Fuel is sold by the gallon in some markets and by the liter in others, so a consumption figure must be converted first.
Reading the result in cubic meters
The cubic meter is the International System unit of volume, the space in a cube with one-meter edges, exactly 1,000 liters or one kiloliter. It is the reference volume against which metric liquid and bulk measurements are defined.
Concrete, water consumption, natural gas, soil, shipping volumes and reservoir capacity are recorded in cubic meters. Utility bills in metric countries often express water and gas use this way.
One cubic meter is exactly 1,000 liters and exactly 35.3146667214886 cubic feet by the exact foot definition. Printed answers are rounded, so a conversion to cubic feet and back may end a digit away.
The common mistake is writing cubic meters for square meters when quoting floor area, or dropping the third dimension when estimating a load. Bulk volume also differs from the capacity of a container.
Cubic meters suit bulk volumes such as water and gas, liters suit bottles and tanks, and cubic feet do the same job on the imperial scale. A decimal point misplaced between cubic meters and liters changes the volume a thousandfold.
Checking a us gallons to cubic meters conversion
The metric volume units are a clean decimal chain around the liter, so liters to milliliters is a shift of three places and cubic meters to liters is a shift of three the other way. Those pairs a reader can do without a converter.
Every pair that names a US or imperial liquid unit has to go through the definition first, because three of these units differ from a metric unit by amounts too large to round away: a liter is not a quart, a gallon is 3.785411784 liters in the US system and 4.54609 in the imperial one, and a US fluid ounce is not an imperial fluid ounce.
When checking a volume conversion, convert into liters and out again, or measure the container. The mistake that survives every other check is reading a US measure as the imperial unit of the same name, which changes a recipe, a fuel figure or a tank size by about a fifth.
Tanzania reference points
Real quantities, converted into the units on this page.
The 20-litre bucket or canister used to carry water in Tanzania
20 L = 5.283441 gal = 0.02 m³
WaterAid puts the minimum daily water need per person at 20 litres, so one container is roughly one person's daily requirement.
Source: IPS News — water access in Tanzania, citing WaterAid · verified 2026-09-14
Related conversions
More volume conversions you can convert instantly.