How many liters means a kilogram

Often you will hear: 1 liter weighs exactly 1 kilogram! Ideally, this is true for one liter of fresh water and is correct enough for household use.

The ideal case here is:

At 3.98 ° C, pure water has a density of 1 dm³ / kg and therefore weighs almost exactly 1 kilogram (999.975 grams). This applies to an air pressure of 1013.25 hPa (1 physical atmosphere), which prevails here on earth at sea level.

At 25 ° C it is 997.048 grams, which means that water at room temperature is around 3 g lighter than at 4 ° C.

These deviations in temperature are irrelevant for applications in the kitchen and household. Likewise, our tap water is never completely pure and always contains salts and other impurities that affect density.

This can be easily calculated with a table of the water density at different temperatures.

Formula for calculating the mass of water
m = p * V
Mass = density x volume

at 4 ° C the calculation is accordingly
0.999975 g / ml x 1,000 ml = 999.975 g

✅ How much does a liter of water weigh?

Anyone who wants to determine 1 liter of water with a scale in the household weighs 1 kg = 1,000 grams (minus the weight for the container).

With 2 liters it is 2 kilograms and with 500 milliliters only 0.5 kg (500 grams) and so on.

✅ How heavy is a liter of milk?

The question: What does 1 liter of milk weigh? cannot be answered precisely across the board. As different amounts of fats, minerals, proteins and other constituents are dissolved in milk - unlike in water - their density is also different - and therefore also their weight.

One liter of cow's milk weighs around 1.02 to 1.03 kilograms.

But here, too, the following applies: For household use, 1 kilogram = 1 liter of milk can easily be used.

This applies to cow's milk as well as to goat and sheep's milk, to almond milk, to soy milk and so on.