Water Weight Calculator
Convert between water volume and weight easily. Calculate how much water weighs in different units with adjustments for temperature.
Note: Water density varies slightly with temperature. This calculator uses standard density values for fresh water at different temperatures. For sea water, a fixed salinity adjustment is applied.
Common Water Weight References
| Water Volume | Weight (approx.) | Notes |
|---|---|---|
| 1 US Gallon | 8.34 pounds | Common reference: "A pint's a pound the world around" |
| 1 Liter | 1 kilogram | At 4°C (maximum density) |
| 1 Cubic Meter | 1000 kilograms (1 tonne) | Base unit for metric system |
| 1 Cubic Foot | 62.4 pounds | Approximately 7.48 gallons |
| 1 Imperial Gallon (UK) | 10.02 pounds | Larger than US gallon (1.2 US gallons) |
About Water Weight
Temperature Effects
Water reaches its maximum density at 4°C (39.2°F). Both heating and cooling from this temperature causes water to become less dense. This is why ice floats on water - water expands when it freezes.
Sea Water vs. Fresh Water
Sea water is approximately 2.5-3% denser than fresh water due to dissolved salts. The density of sea water depends on its salinity, but averages around 1,026 kg/m³ compared to fresh water's 1,000 kg/m³ at 4°C.
Practical Applications
Understanding water weight is essential for various applications including shipping, construction, engineering, chemistry, cooking, and more. For instance, when designing water tanks, calculating the structural support needed depends directly on the weight of the water to be contained.