Water Volume & Weight Calculator

Physical Properties & Volume-Weight Equivalencies

In the metric system, the unit of mass (the kilogram) was historically defined as the mass of one liter of water at its freezing melting point. This creates simple, elegant unit equivalencies.

Standard Volume Equivalents

• 1 Liter = 1,000 mL = 1,000 cm³ = 0.264172 US Gallons
• 1 US Gallon = 3.78541 Liters = 231 cubic inches = 0.133681 ft³
• 1 Imperial Gallon = 4.54609 Liters = 1.20095 US Gallons
• 1 Cubic Foot = 7.48052 US Gallons = 28.3168 Liters
• 1 Cubic Meter = 1,000 Liters = 264.172 US Gallons = 35.3147 ft³

Density of Water at Different Temperatures

Water volume to weight – calculation example

Let’s see how to calculate the total mass of a water container:

1. First, enter the water volume: volume = 55 US gallons.
2. Select the temperature: temperature = 20°C (68°F).
3. Check the liquid density: density = 998.2 kg/m³.
4. The calculation results are available for you: mass = 458.2 lbs and volume in liters = 208.2 L.

💡 Pure water reaches its maximum density of 1,000 kg/m³ at 3.98°C (39.2°F). As water warms or freezes, it expands and becomes less dense.