Gallons to Tons Converter
This converter calculates the mass of any liquid in US short tons, metric tonnes, or UK long tons given its volume in gallons - or works in reverse from tons to gallons. Pick a substance from the dropdown (or enter a custom density), choose US or Imperial gallons and your preferred ton type, and the result updates instantly. Every step of the math is shown in the "Show your work" panel below the result.
Formula
Worked example
100 US gallons of fresh water: 100 × 3.785411 L × 1.0000 kg/L = 378.54 kg. In short tons: 378.54 ÷ 907.18 = 0.4173 ST. In metric tons: 378.54 ÷ 1000 = 0.3785 t. In long tons: 378.54 ÷ 1016.05 = 0.3726 LT.
Why gallons and tons cannot convert without a density
A gallon measures volume - how much space a liquid takes up. A ton measures mass - how heavy it is. Those are fundamentally different physical quantities, so there is no single fixed number to multiply by. You also need to know how dense the liquid is. One US gallon of fresh water weighs about 8.34 pounds (3.79 kg), while the same volume of gasoline weighs only about 6.25 pounds (2.84 kg) because gasoline is about 25% less dense than water. Diesel, jet fuel, seawater, and other common industrial liquids all have distinct densities, and this converter includes preset values for each of them. If your liquid is not listed, enter its density in kg/L in the custom density field.
Short tons, metric tons, and long tons - what is the difference?
There are three common types of "ton", and the difference matters. The US short ton is exactly 2,000 pounds (907.18 kg) and is used in the United States for most commercial and industrial applications. The metric ton (also called a tonne) is exactly 1,000 kg (2,204.6 lb) and is the standard in international trade and scientific work. The UK long ton is 2,240 pounds (1,016.05 kg) and is used in some maritime and historical British contexts. A given mass is about 10% smaller in short tons than in metric tons, and about 10% smaller in metric tons than in long tons. This converter shows all three side by side so you can compare at a glance.
US gallons vs Imperial gallons
The US liquid gallon (3.7854 litres) and the Imperial gallon used in the UK and Canada (4.5461 litres) differ by almost exactly 20%. One Imperial gallon equals about 1.2009 US gallons. This distinction matters most in fuel and agricultural contexts: a shipping manifest stating "1,000 gallons" means very different quantities depending on which standard is being used. This converter lets you switch between the two gallon types with a single tap.
How to use this converter for shipping and industrial applications
Fuel and bulk-liquid shipments are often quoted in volume (gallons, barrels, or cubic metres) but taxed, insured, or documented by mass (short tons or metric tonnes). To convert, first confirm the substance and its density at the actual temperature of measurement, as density decreases with temperature - diesel at 0 °C is noticeably denser than diesel at 40 °C. Then select the correct gallon type and ton type for your jurisdiction or contract, enter your volume, and read off the mass. The "Tons to gallons" mode is useful when you have a weight-based purchase order and need to estimate the number of tanker loads or storage tanks required.
Density of common liquids
| Substance | Density (kg/L) | US gal to short tons | US gal to metric tons |
|---|---|---|---|
| Fresh water (4 °C) | 1 | 0.003749 | 0.003785 |
| Seawater (3.5% sal.) | 1.025 | 0.003842 | 0.00388 |
| Whole milk | 1.03 | 0.00386 | 0.003899 |
| Crude oil (medium) | 0.87 | 0.003258 | 0.003293 |
| Diesel fuel | 0.85 | 0.003183 | 0.003215 |
| Jet fuel (Jet A) | 0.8 | 0.002995 | 0.003028 |
| Ethanol | 0.7893 | 0.002955 | 0.002988 |
| Gasoline (petrol) | 0.749 | 0.002804 | 0.002832 |
Reference densities at approximately 15-20 °C. Use the custom density option for exact values.
Frequently asked questions
How many gallons are in a ton of water?
For fresh water at 4 °C (its maximum density, 1.000 kg/L): 1 US short ton (907.18 kg) = approximately 239.65 US gallons. 1 metric ton (1,000 kg) = approximately 264.17 US gallons. 1 UK long ton (1,016.05 kg) = approximately 268.4 US gallons. In Imperial gallons, those figures are about 199.5, 219.97, and 223.54 respectively.
How many gallons of diesel are in a short ton?
Diesel fuel has a density of about 0.850 kg/L. One US short ton of diesel (907.18 kg) equals approximately 907.18 / 0.850 = 1,067.3 kg/L of volume, which is 1,067.3 / 3.785 = 281.9 US gallons. Because diesel is less dense than water, a ton of diesel occupies more gallons than the same ton of water.
Can I use this for gasoline or petrol?
Yes. Select "Gasoline (petrol)" from the substance dropdown. Gasoline has a density of about 0.749 kg/L, which means it is about 25% lighter than water by volume. One US short ton of gasoline is approximately 320.9 US gallons - notably more than the 239.6 gallons for the same ton of water.
What is the difference between a US gallon and an Imperial gallon?
The US liquid gallon is exactly 231 cubic inches, equal to 3.785411784 litres. The Imperial gallon, used in the UK and Canada, is defined as 4.54609 litres - about 20% larger. When a calculation says "gallons" without specifying, it nearly always means US gallons in an American context and Imperial gallons in a British or Canadian context. This converter lets you select the type so your result is accurate.
Why does temperature affect the conversion?
Most liquids expand when heated, so the same mass occupies a larger volume at higher temperatures. Water at 20 °C has a density of about 0.998 kg/L, while at 80 °C it drops to about 0.972 kg/L - a 2.6% difference. For precise industrial or custody-transfer calculations, use the actual density of the liquid at the operating temperature rather than the reference value. Enter it in the custom density field.
How do I convert tons to gallons instead of gallons to tons?
Switch the "Direction" dropdown to "Tons to gallons". Enter the mass in the ton type of your choice (short, metric, or long) and select the substance. The calculator divides the mass by the density to get the volume in litres, then converts litres to gallons of the type you selected.