how much does a liter of water weigh

A liter of liquid water weighs about 1 kilogram, which is 1,000 grams or roughly 2.2 pounds under normal conditions near room temperature.

Quick Scoop

• In the metric system, 1 liter of water ≈ 1 kilogram (kg).

• That’s 1,000 grams (g) per liter.

• In everyday U.S. terms, 1 liter of water weighs about 2.2 pounds (lb).

• The exact weight changes slightly with temperature: at 4°C it’s essentially exactly 1 kg; at typical room temperature it’s just under 1 kg (about 998 g).

Why it works out so neatly

Water’s density is about 1 kilogram per liter under standard conditions, meaning every milliliter of water has a mass of about 1 gram. Since there are 1,000 milliliters in a liter, that adds up to about 1,000 grams, i.e., 1 kilogram.

For quick mental math, you can safely treat “1 liter of water = 1 kilogram = about 2.2 pounds” for most everyday uses.

TL;DR: A liter of water weighs about 1 kg (1,000 g, ~2.2 lb), with only tiny variations depending on temperature and conditions.