5 gallons of water weighs about 41.7 pounds (18.9 kg). One US gallon of fresh water weighs 8.34 lb near 60 °F, so multiply by 5 and add the weight of the bucket or jug. The calculator below does the same math for fuels, oils, milk, honey, paint and antifreeze, in either direction.
How much does 5 gallons of water weigh?
The water in a standard 5-gallon jug or bucket weighs 41.7 lb, or 18.9 kg. That figure comes from the density of water at 60 °F in the NIST Chemistry WebBook: 999.017 kg per cubic meter, which works out to 8.34 lb per US gallon. Temperature barely moves it — the same 5 gallons weighs 41.7 lb near freezing and 40 lb near boiling.
What you actually lift is the water plus the container. Jugs and buckets vary, so weigh yours empty on a bathroom scale and add it to 41.7 lb. If you meant 5 imperial (UK) gallons, the water weighs about 50.1 lb.
How to use this calculator
- Choose the liquid from the list. Water, seawater, fuels, food liquids, paint and antifreeze are included.
- Pick the direction: Volume → weight to weigh a known amount, or Weight → volume to find out how many gallons a given weight is.
- Enter the amount and choose its unit: US gallons, UK gallons, liters, quarts, fluid ounces or cubic feet (or lb, kg, oz, US tons or tonnes for weight).
- Read the result in pounds, with kilograms and ounces underneath — or, in reverse mode, US gallons with liters and UK gallons.
- Use Share to copy a link with your inputs filled in.
Weight per gallon chart (pounds)
Weight of 1, 5 and 55 US gallons, the three amounts people ask about most (a jug, a bucket, a steel drum). Values are for the liquid only, near 60 °F.
| Liquid | 1 gallon | 5 gallons | 55 gallons (drum) |
|---|---|---|---|
| Water (fresh) | 8.34 lb | 41.7 lb | 459 lb |
| Seawater | 8.55 lb | 42.8 lb | 470 lb |
| Diesel fuel | 7.1 lb | 35.5 lb | 391 lb |
| Gasoline | 6.2 lb | 31 lb | 341 lb |
| Kerosene | 6.7 lb | 33.5 lb | 369 lb |
| Jet fuel (Jet A) | 6.7 lb | 33.5 lb | 369 lb |
| Propane (liquid) | 4.2 lb | 21 lb | 231 lb |
| Ethanol | 6.6 lb | 33 lb | 363 lb |
| Milk | 8.6 lb | 43 lb | 473 lb |
| Vegetable oil | 7.7 lb | 38.5 lb | 424 lb |
| Honey | 11.8 lb | 59 lb | 649 lb |
| Maple syrup | 11 lb | 55 lb | 605 lb |
| Latex paint (typical, estimate) | 10 lb | 50 lb | 550 lb |
| Antifreeze concentrate (100% ethylene glycol) | 9.3 lb | 46.5 lb | 512 lb |
| Antifreeze 50/50 with water | 8.9 lb | 44.5 lb | 490 lb |
Weight per gallon chart (kilograms)
| Liquid | 1 gallon | 5 gallons | 55 gallons (drum) |
|---|---|---|---|
| Water (fresh) | 3.78 kg | 18.9 kg | 208 kg |
| Seawater | 3.88 kg | 19.4 kg | 213 kg |
| Diesel fuel | 3.22 kg | 16.1 kg | 177 kg |
| Gasoline | 2.81 kg | 14.1 kg | 155 kg |
| Kerosene | 3.04 kg | 15.2 kg | 167 kg |
| Jet fuel (Jet A) | 3.04 kg | 15.2 kg | 167 kg |
| Propane (liquid) | 1.91 kg | 9.5 kg | 105 kg |
| Ethanol | 2.99 kg | 15 kg | 165 kg |
| Milk | 3.9 kg | 19.5 kg | 215 kg |
| Vegetable oil | 3.49 kg | 17.5 kg | 192 kg |
| Honey | 5.35 kg | 26.8 kg | 294 kg |
| Maple syrup | 4.99 kg | 24.9 kg | 274 kg |
| Latex paint (typical, estimate) | 4.54 kg | 22.7 kg | 249 kg |
| Antifreeze concentrate (100% ethylene glycol) | 4.22 kg | 21.1 kg | 232 kg |
| Antifreeze 50/50 with water | 4.04 kg | 20.2 kg | 222 kg |
How it's calculated
weight (lb) = volume (US gal) × density (lb/gal)
- Volume is converted to US gallons first. One US gallon is 231 cubic inches, or exactly 3.785411784 liters (NIST Handbook 44, Appendix C). A UK gallon is 4.54609 liters (UK Weights and Measures Act 1985), which is 1.20095 US gallons. A cubic foot is 7.48052 US gallons.
- Density is the typical weight of one US gallon of that liquid near 60 °F, taken from government references: NIST for water and propane, USGS for seawater, EPA and DOE for fuels, FAA for jet fuel, USDA for milk, oils, honey and syrup.
- Kilograms use the exact definition 1 lb = 0.45359237 kg (NIST Handbook 44).
Reverse mode divides instead: gallons = weight ÷ density.
Worked examples
Example 1: a 5-gallon water jug
5 gal × 8.34 lb/gal = 41.7 lb of water, or 18.9 kg. Add the empty jug.
Example 2: a 55-gallon drum of diesel
55 gal × 7.1 lb/gal = 390.5 lb (177 kg) of fuel. The same drum full of water would hold 458.7 lb, so a drum of diesel is about 68 lb lighter than a drum of water.
Example 3: how many gallons in a 20 lb propane tank?
20 lb ÷ 4.2 lb/gal = 4.76 gallons of liquid propane. This is why a tank sold by weight holds fewer gallons than its size suggests — propane weighs about half as much as water.
Water weight by temperature
In the table below, water is heaviest near freezing and gets lighter as it warms. These values are calculated from the NIST Chemistry WebBook density of liquid water at normal atmospheric pressure.
| Temperature | Density | 1 US gallon | 5 US gallons |
|---|---|---|---|
| 0 °C (32 °F) | 999.844 kg/m³ | 8.344 lb | 41.72 lb |
| 10 °C (50 °F) | 999.702 kg/m³ | 8.343 lb | 41.71 lb |
| 20 °C (68 °F) | 998.205 kg/m³ | 8.33 lb | 41.65 lb |
| 30 °C (86 °F) | 995.646 kg/m³ | 8.309 lb | 41.55 lb |
| 40 °C (104 °F) | 992.213 kg/m³ | 8.28 lb | 41.4 lb |
| 60 °C (140 °F) | 983.191 kg/m³ | 8.205 lb | 41.03 lb |
| 80 °C (176 °F) | 971.784 kg/m³ | 8.11 lb | 40.55 lb |
| 100 °C (212 °F) | 958.367 kg/m³ | 7.998 lb | 39.99 lb |
What affects the result
- The container. Every figure on this page is the liquid only. Buckets, jugs, drums and tanks add their own weight.
- US vs UK gallons. A UK gallon is about 20% bigger, so everything in it weighs about 20% more. Pick the right unit.
- Temperature. Warm liquids expand and weigh less per gallon. For water the change from near-freezing to near-boiling is about 4%. Fuels and oils also expand with heat, so a gallon weighed on a hot day comes out slightly light.
- Product and blend. Diesel, gasoline and paint vary by formulation. Paint is the widest: the 10 lb figure here is an estimate, and the product's technical data sheet gives the real number.
- Mixtures. Antifreeze mixed 50/50 with water weighs between water and pure glycol. Seawater is heavier than fresh water because of dissolved salt.
When not to use this calculator
Use a certified scale, not an estimate, when weight matters legally or for safety — for example vehicle and trailer loading limits, aircraft weight and balance, or shipping declarations. For compressed gases other than liquid propane, and for pressurized or heated tanks, weight per gallon depends on pressure and temperature in ways a single typical value can't capture.
Related questions
Why do oil and gasoline float on water?
Anything that weighs less per gallon than water and doesn't mix with it floats. Gasoline (6.2 lb/gal), diesel (7.1) and vegetable oil (7.7) are all lighter than water (8.34); honey (11.8) and maple syrup (11) sink.
How much water is in a cubic foot or a tank?
A cubic foot holds 7.48 gallons and its water weighs about 62.4 lb. To find the volume of a tank or tub first, use the cubic feet calculator, then enter the result here in ft³.
How much pressure does a column of water create?
Weight and pressure are linked: the taller the water, the more it pushes down. The water column to psi converter handles that. For small kitchen amounts, the mL to oz converter is quicker.
For solids sold by volume, such as topsoil, gravel or mulch, the cubic yard calculator gives weight per yard and total tons.
Frequently asked questions
How much does 5 gallons of water weigh?
About 41.7 lb (18.9 kg): 5 × 8.34 lb per US gallon at 60 °F. The bucket or jug adds its own weight on top, so a full container weighs a little more.
How much does a 5 gallon jug of water weigh when full?
The water alone is about 41.7 lb (18.9 kg). Add the empty weight of your jug, which depends on its material and wall thickness; weigh it empty or check the label.
How much does 1 gallon of water weigh?
About 8.34 lb (3.78 kg) per US gallon near 60 °F. A UK (imperial) gallon of water weighs about 10.02 lb because it is about 20% larger.
How much does a gallon of diesel weigh?
About 7.0–7.1 lb (3.22 kg) per US gallon. EPA uses 7.1 lb, and DOE's GREET model gives 6.98 lb for conventional diesel and 7.07 lb for ultra-low-sulfur diesel. 5 gallons is about 35.5 lb.
How much does a gallon of gasoline weigh?
About 6.2 lb (2.81 kg) per US gallon (DOE GREET: 2,819 g per gallon for conventional gasoline). It is lighter than water and doesn't mix with it, so it floats.
How much does a gallon of propane weigh?
Liquid propane weighs about 4.2 lb per gallon. A '20 lb' BBQ tank holds about 4.8 gallons of liquid propane.
How much does a gallon of paint weigh?
Latex paint is usually about 8.5–11.2 lb per gallon depending on the product, based on manufacturer data sheets; this calculator uses 10 lb as a typical estimate. Check the weight-per-gallon line on your paint's technical data sheet.
How much does a 55 gallon drum of water weigh?
The water in a full 55-gallon drum weighs about 459 lb (208 kg). The drum itself is extra. The same drum filled with diesel holds about 391 lb of fuel.
Does hot water weigh less than cold water?
Slightly. Using NIST density data, a US gallon of water weighs about 8.344 lb near freezing and about 7.998 lb near boiling — roughly a 4% difference.
How much does a cubic foot of water weigh?
About 62.4 lb. A cubic foot holds 7.481 US gallons, and each gallon weighs about 8.34 lb.
How much does a liter of water weigh?
Almost exactly 1 kg: 0.998 kg at 20 °C per NIST density data, or about 2.2 lb.
Sources & method
- NIST Handbook 44 (2026) Appendix C — 1 US gal = 231 in³; 1 lb = 0.45359237 kg
- NIST Chemistry WebBook SRD 69 — density of water at 1 atm, 0–100 °C
- UK Weights and Measures Act 1985, Schedule 1 — UK gallon = 4.54609 L
- USDA ERS AH-697 — Weights, measures and conversion factors (milk, oil, honey, syrup)
- EPA AP-42 §7.1 — properties of petroleum liquids (diesel, ethanol)
- FAA-H-8083-1B Weight & Balance Handbook — fuel weights
- NOAA CAMEO Chemicals — kerosene
- USGS TWRI 6-A7 — seawater density 1,025 kg/m³
- PubChem — ethylene glycol density
Results are estimates for general information. Found an error? It helps everyone — see our methodology.