Water Volume to Weight Converter
Convert water volume to weight and back: gallons, liters, cups and cubic feet to pounds, kilograms and ounces, at different water temperatures.
· CalcFlow Editorial
1 gal = 8.3304411 lb
Results shown are estimates for informational purposes only. Nothing on CalcFlow is financial, tax, legal, or medical advice. Always consult a qualified professional before making important decisions.
Common Water Weight Conversions
| Water volume | Kilograms | Pounds |
|---|---|---|
| 1 L | 0.998207 | 2.2006697 |
| 5 L | 4.991035 | 11.003349 |
| 10 L | 9.98207 | 22.006697 |
| 20 L | 19.96414 | 44.013395 |
| 50 L | 49.91035 | 110.03349 |
| 100 L | 99.8207 | 220.06697 |
| 1 US gal | 3.7786245 | 8.3304411 |
| 5 US gal | 18.893123 | 41.652206 |
| 10 US gal | 37.786245 | 83.304411 |
| 50 US gal | 188.93123 | 416.52206 |
Popular Water Weight Conversions
Formula
mass = volume x density (water at 20 C is 0.998207 g/mL; 1 US gal = 3.785411784 L)Understanding Water Weight Conversion
The metric system was built around water: one liter of pure water at its densest, about 4 degrees C, has a mass of almost exactly one kilogram. At room temperature the figure is 0.998 kg per liter, and hot water is lighter per liter. A US gallon of fresh water weighs about 8.33 pounds, and a cubic foot weighs about 62.3 pounds. Seawater is about 2.5 percent denser than fresh water because of dissolved salt.
Tips and Best Practices
- 1For quick estimates use 1 liter = 1 kilogram and 1 US gallon = 8.34 pounds.
- 2A 50 gallon water heater holds roughly 416 pounds of water when full.
- 3Use the temperature selector for hot or cold water if precision matters.
Real-World Example
A 10 US gallon aquarium holds 10 x 3.785411784 x 0.998207 = 37.79 kg of fresh water at 20 C, about 83.3 pounds.
Common Mistakes to Avoid
- Using the US gallon figure (8.33 lb) for an imperial gallon, which holds about 10.0 lb.
- Forgetting that a container adds its own weight to the water.
- Using 1 kg per liter for seawater or brine.
How to Use
- Pick the unit you have in the left selector and the unit you want in the right selector.
- Type a number in either box; the other box updates instantly.
- Use the swap button to reverse the direction and Copy result to copy the answer.
Frequently Asked Questions
How much does a gallon of water weigh?
How much does a liter of water weigh?
How much does a cubic foot of water weigh?
Sources: Water density from the CRC Handbook of Chemistry and Physics (g/mL): 4 C 0.999975, 20 C 0.998207, 25 C 0.997048, 100 C 0.958365; seawater is typically about 1.025. Volume units: NIST Handbook 44 Appendix B.