Gallons to Pounds Converter
Pick a liquid, enter the volume in US gallons, and get the weight in pounds instantly. The tool covers water at three temperatures, milk, beer, honey, gasoline, diesel, olive oil, and more than 20 other common substances. Need pounds to gallons instead? Flip the direction switch. Have an unusual liquid? Enter its density directly in the custom mode.
Formula
Worked example
5 gallons of whole milk: density = 8.637 lb/gal, so 5 x 8.637 = 43.19 lb. Reverse: 43.19 lb / 8.637 = 5.00 gal.
Why gallons and pounds need a density bridge
A gallon measures volume (the space a liquid fills), and a pound measures mass (the amount of matter). Because different liquids pack different amounts of matter into the same space, there is no single number that converts all gallons to pounds. One US gallon of water weighs about 8.33 lb, one gallon of honey weighs nearly 12 lb, and one gallon of gasoline weighs only about 6.15 lb. The missing piece is density: once you know how many pounds fit in one gallon of the specific liquid, you simply multiply by the number of gallons. The formula is: pounds = gallons x density (lb/gal). To go the other way, pounds to gallons, divide instead: gallons = pounds / density (lb/gal).
How to use this converter
Select the substance from the dropdown. More than 20 common liquids are pre-loaded with their standard densities. Choose whether you are converting gallons to pounds or pounds to gallons, then enter the volume or weight. The result, the density applied, and a breakdown of the calculation appear instantly. If your liquid is not in the list, choose "Custom substance" and enter the density from the product label or safety data sheet (SDS). Density may be printed in lb/gal, kg/L, or g/cm3; to convert kg/L to lb/gal, multiply by 8.3454. Temperature matters: water is densest at 39 F (4 C) and becomes lighter when heated, so the presets offer water at three temperatures.
Density of common liquids
Water at room temperature (68 F / 20 C) weighs about 8.33 lb per US gallon. Milk is slightly denser at 8.64 lb/gal because of dissolved proteins and fats. Honey is notably heavier at around 11.85 lb/gal. Petroleum products span a wide range: propane is the lightest at about 4.24 lb/gal, gasoline sits around 6.15 lb/gal, and diesel is heavier at 7.09 lb/gal. Vegetable oils run roughly 7.5 to 7.6 lb/gal, lighter than water because oil floats. Paint varies considerably by formulation; a typical interior latex paint averages about 10 lb/gal. The reference table below lists 1, 2, 5, and 10-gallon weights for the most searched substances.
US gallons vs UK (imperial) gallons
This converter uses US liquid gallons throughout. One US liquid gallon equals 231 cubic inches or approximately 3.785 litres. A UK (imperial) gallon is larger, at about 4.546 litres, meaning the same volume label means more liquid and more weight in the UK system. If you are working with UK gallons, multiply the US-gallon result by 1.2009, or divide a UK-gallon figure by 1.2009 before entering it here. Fuel economy figures in the UK and Canada also use imperial gallons, so always confirm which system a specification uses before converting.
Gallons to pounds: common liquids
| Substance | Density (lb/gal) | 1 gal | 2 gal | 5 gal | 10 gal |
|---|---|---|---|---|---|
| Water (room temp) | 8.326 | 8.33 lb | 16.65 lb | 41.63 lb | 83.26 lb |
| Water (max density) | 8.345 | 8.35 lb | 16.69 lb | 41.73 lb | 83.45 lb |
| Milk (whole) | 8.637 | 8.64 lb | 17.27 lb | 43.19 lb | 86.37 lb |
| Beer | 8.430 | 8.43 lb | 16.86 lb | 42.15 lb | 84.30 lb |
| Wine | 8.480 | 8.48 lb | 16.96 lb | 42.40 lb | 84.80 lb |
| Orange juice | 8.680 | 8.68 lb | 17.36 lb | 43.40 lb | 86.80 lb |
| Honey | 11.850 | 11.85 lb | 23.70 lb | 59.25 lb | 118.50 lb |
| Olive oil | 7.580 | 7.58 lb | 15.16 lb | 37.90 lb | 75.80 lb |
| Vegetable oil | 7.550 | 7.55 lb | 15.10 lb | 37.75 lb | 75.50 lb |
| Gasoline | 6.152 | 6.15 lb | 12.30 lb | 30.76 lb | 61.52 lb |
| Diesel fuel | 7.094 | 7.09 lb | 14.19 lb | 35.47 lb | 70.94 lb |
| Jet fuel (Jet-A) | 6.710 | 6.71 lb | 13.42 lb | 33.55 lb | 67.10 lb |
| Liquid propane | 4.235 | 4.24 lb | 8.47 lb | 21.18 lb | 42.35 lb |
| Paint (latex) | 10.000 | 10.00 lb | 20.00 lb | 50.00 lb | 100.00 lb |
| Household bleach | 9.560 | 9.56 lb | 19.12 lb | 47.80 lb | 95.60 lb |
Weight of 1, 2, 3, 5, and 10 US gallons for frequently converted substances at typical room temperature.
Frequently asked questions
How many pounds is 1 gallon of water?
One US gallon of water weighs approximately 8.33 pounds at room temperature (68 F / 20 C). At its maximum density of 39.2 F (4 C), one gallon of water weighs 8.3452 lb. At boiling point (212 F / 100 C), the same volume weighs about 7.996 lb because heat expands the water and lowers its density.
How many pounds is 5 gallons of water?
5 gallons of water weighs about 41.63 lb at room temperature (5 x 8.3264 = 41.63). At maximum density the answer is 5 x 8.3452 = 41.73 lb. This is a common calculation for five-gallon buckets and water cooler jugs.
How do I convert gallons to pounds without a calculator?
Multiply the number of gallons by the density of the liquid in pounds per gallon (lb/gal). For water, use 8.33 as a quick approximation: 3 gallons of water is roughly 3 x 8.33 = 24.99 lb. For other liquids, look up the density on the product label or data sheet. The formula is simply: pounds = gallons x density (lb/gal).
Does temperature affect how many pounds are in a gallon?
Yes. All liquids change density with temperature, so the weight of one gallon changes as the liquid heats or cools. Water is the clearest example: it weighs 8.3452 lb/gal at its densest (39 F) and only 7.996 lb/gal at boiling point. For most practical purposes the difference is small, but it matters in precise industrial or scientific contexts where you should use the density at the actual operating temperature.
How many pounds is a gallon of gasoline?
One US gallon of gasoline weighs approximately 6.15 pounds. Gasoline is significantly lighter than water because its hydrocarbon molecules are less dense. For a full 15-gallon fuel tank, that works out to roughly 92 pounds of gasoline.
How many pounds is a gallon of milk?
One US gallon of whole milk weighs about 8.64 pounds, slightly heavier than water because milk contains dissolved proteins, fats, and lactose that increase its density. Skim milk is marginally lighter. The variation between milk types is small enough that 8.6 lb/gal is a reliable estimate for most purposes.
What is the difference between US gallons and imperial gallons?
A US liquid gallon equals 3.785 litres. A UK (imperial) gallon equals 4.546 litres, making it about 20% larger. The same 8 "gallons" of water weighs about 66.6 lb in US gallons but 79.4 lb in imperial gallons. Always check which system a specification uses; fuel economy ratings in the UK and Canada use imperial gallons.