Water weight calculator
Calculate water mass using a density you can adjust.
Formula
Mass (kg) = volume (L) × density (kg/m³) / 1000; lb = kg / 0.45359237.
Water volume: 5 US gal · Water mass ≈ (5 US gal × 3.785411784 L/US gal)×(1,000)÷1000 · Water mass in pounds ≈ (18.92705892)÷0.45359237
How to use
- Enter the water volume and select its unit.
- Enter density for your water and temperature.
- Read water mass in kilograms and pounds.
Examples
- At 998.02 kg/m³, 1,000 L of water has a mass of 998.02 kg.
Frequently asked questions
Does 1 liter of water weigh 1 kg?
Approximately. The default 1,000 kg/m³ is rounded; temperature and dissolved substances change density.
What about hot water or seawater?
Enter a measured or reliable density for those conditions. No temperature or salinity model is applied.
Is container weight included?
No. Results are water mass only, not container mass or gravitational force in newtons.
Sources
Updated: