Water Weight Calculator
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How much does water weigh?
The weight of a volume of water depends upon the temperature at which it is being stored. This is because water expands as it gets warmermeaning that hot water weighs lessand cold water weighs more (because it's more dense).
Water reaches its highest density at a temperature near freezing. As it begins to freezeit starts to expand and therefore becomes less dense again.
In order to accurately convert a volume of water to a weight in gramsounces or poundsa density figure needs to be factored in. 1
At room temperature (70°F / 21°C)the density of water is 0.99802 g/ml. This means that the weight of a US gallon of water at room temperature is around 8.33 pounds.To calculate the weight of a gallon of another liquidyou can use our gallons to pounds converter.
How much does 1 liter of water weigh?
One liter of water at room temperature (70°F / 21°C) weighs approximately 1 kilogram (35.2 ounces or 2.2lb). The density of water at room temperature is around 1g/ml (0.998 g/ml).
How much does 500ml of water weigh?
500ml of water at room temperature (70°F / 21°C) weighs approximately 500 grams (17.6 ounces or 1.1lb). This is because the density of water at room temperature is around 1g/ml (0.998 g/ml).
How much does a 16.9 oz bottle of water weigh?
A 16.9 fl oz bottle of water at room temperature (70°F / 21°C) weighs approximately 17.595 ouncesor 1.1lbplus the weight of the bottle. For a plastic 16.9 oz bottle of around 0.35 ounces (0.022lb)you're looking at a total weight of around 17.95 ounces or 1.12lb.
These conversions reference the US fluid ounce (29.57ml) rather than the UK Imperial fluid ounce (28.41ml).
Calculating the weight of water
To work out the weight of a container of wateryou'll need a couple of figures: the volume of water and the density of the water (ideally in g/mlfor this example). Before you begin your conversion you'll need to convert your volume figure to milliliters (mL) first. You can use our volume converter for this if you need to. Orif your volume of water is in gallonsyou can convert to liters here.
Example: 1L of water at room temperature
Water density at room temperature: 0.99802 g/ml
- Convert your 1L figure to mL
Volume = 1 × 1000 = 1000mL - Weight in grams = volume × density
1000 × 0.99802 = 998.02g - Convert grams to pounds
998.02 × 0.0022 = 2.1956 lb
To make things easierand assuming you require a rough estimateyou could use a straight density figure of 1g/ml. This assumes a water temperature of 39.2°F / 4.0°C. If you need help with your conversionyou can use our ml to grams conversion tool.
Water density chart
The following water density figures are from the U.S. Department of the InteriorBureau of Reclaimation1977Ground Water Manualfrom The Water EncyclopediaThird EditionHydrologic Data and Internet Resources. 2
| Water temp (°F / °C) | Density (g/ml) |
|---|---|
| 32°F / 0°C | 0.99987 |
| 39.2°F / 4.0°C | 1.00000 |
| 40°F / 4.4°C | 0.99999 |
| 50°F / 10°C | 0.99975 |
| 60°F / 15.6°C | 0.99907 |
| 70°F / 21°C (room temp) | 0.99802 |
| 80°F / 26.7°C | 0.99669 |
| 90°F / 32.2°C | 0.99510 |
| 100°F / 37.8°C | 0.99318 |
| 120°F / 48.9°C | 0.98870 |
| 140°F / 60°C | 0.98338 |
| 160°F / 71.1°C | 0.97729 |
| 180°F / 82.2°C | 0.97056 |
| 200°F / 93.3°C | 0.96333 |
| 212°F / 100°C | 0.95865 |
References
- The Physics Factbook. Density of Water. Edited by Glenn Elert.
- United States Geological Survey. Water Density. Water Science School.
- PET Resin Association. Little-Known Facts about PET Plastic.
If you have any problems using our water weight calculatorplease contact us.