How Heavy Is a Liter of Water?
a Liter of Water weighs about
1 kg (2.2 lb)
Computed value (volume × density); the inputs are cited under Sources below.
- a domestic cat4.5 kg
adult domestic cat (Felis catus); males larger; range 4.1–5.4 kg
- a gallon of water3.78 kg
1 US gallon (3.785 412 L) of pure water at 4 °C
- a liter of water1 kg
1 litre (1 L) of pure water at 4 °C
- an iPhone 160.17 kg
iPhone 16, Apple technical specifications
- You
Open full comparison → to add more objects on one scale.
Put it in perspective
- About 3.8× a gallon of water
- About 4.5× a domestic cat
- About 5.9× an iPhone 16
Why weights differ
The litre is exact by definition; only the density depends on temperature. At 4 °C water is at its densest, so a litre is very slightly under 1 kg.
Sources
[1] National Institute of Standards and Technology
NIST Guide to the SI, Appendix B.9: Factors for units listed by kind of quantity or field of scienceStandard body
“liter (L) 19 cubic meter (m 3 ) 1.0 E-03”
Value as published: 1 liter (L) = 1.0E-03 m3 · accessed 2026-11-11.
[2] U.S. Geological Survey
Water DensityGovernment agency
“the exact density of water is not really 1 g/ml, but rather a bit less (very, very little less), at 0.9998395 g/ml at 4.0° Celsius”
Value as published: 0.9998395 g/ml at 4.0 °C · accessed 2026-11-11.
How this value was computed
- volume-l: 1 L — 来源 [1] (source [1])
- density-kg-per-l: 0.9998395 kg/L — 来源 [2] (source [2])
Last updated 2026-11-11.Report a correction (please include a source link).
Related objects
- a loaf of bread0.567 kg (1.25 lb)
- a 5 lb bag of flour2.268 kg (5 lb)
- a can of soda370 g (0.816 lb)
- a gallon of water3.78 kg (8.34 lb)
- a gallon of milk3.9 kg (8.61 lb)
- a watermelon4.52 kg (9.96 lb)
Frequently asked questions
How much does a liter of water weigh?
a Liter of Water weighs about 1 kg (2.2 lb) — 1 litre (1 L) of pure water at 4 °C.
How much is a liter of water in pounds and ounces?
2.2 lb, which is 35.3 oz. In metric terms: 1 kg.
Is a liter of water heavier than a gallon of water?
No. a Liter of Water weighs about 1 kg (2.2 lb), while a gallon of water is about 3.78 kg (8.34 lb) — roughly 1/3.79.
Why do sources give different weights?
The litre is exact by definition; only the density depends on temperature. At 4 °C water is at its densest, so a litre is very slightly under 1 kg.
Where does this number come from?
Every source is listed at the bottom of this page with publisher, link, access date and a verbatim quote. Numbers are only published when a qualifying source can be verified.