How many pounds is 4.2 liters?
How many pounds is 4.2 liters?
Answer
The question names no substance, so the answer above is for water — the usual reference, taken at 20 °C (68 °F). Other liquids weigh differently at the same volume: across the table below 4.2 liters runs from 4.7 lbs (propane) to 9.24 lbs (water).
In kilograms, 4.2 liters of water is 4.19 kg — the same density, answered by the liters to kilograms page.
How the weight of 4.2 liters of water was worked out
A pound is exactly 0.45359237 kilograms, so the density in kilograms per liter turns into pounds per liter by dividing by the pound.
4.2 L × 0.998 kg/L ÷ 0.45359237
≈9.24 lbs
(nine point two four lbs)
The density comes from FAO/INFOODS Density Database v2.0: liquid water at 20 °C; rounding to 1.00 kg/L is fine for everyday use.
Why the same liter weighs differently
A liter measures volume, a pound measures weight, and density is what ties them together: how many pounds one liter of this particular substance comes to. Water is the everyday reference at 2.2 lbs per liter, and everything else sits above or below it.
Across this page the spread is wide: one liter of propane weighs 1.12 lbs, one liter of water 2.2 lbs — at the very same volume.
The other way round: how many liters a weight fills
This page starts from a volume and answers in pounds. The opposite question — how many liters a given weight comes to — is what the pounds to liters calculator is for, and in metric units the same question is kilograms to liters. All of them read one density table, so their numbers agree.
For water that means 4.2 liters weighs 9.24 lbs here, and one pound of it fills 0.45 liters there.
Related Calculations
See Also
- Pounds to Liters - How many liters a pound of water, milk, oil or propane takes — by density
- Liters to Kilograms - How many kilograms are in a liter of water, honey, gasoline, sand and other substances — by density
- Gallons to Pounds - How much a gallon of water, milk, gasoline, diesel, oil or propane weighs in pounds — by density
- Kg to Lbs - Convert Kilograms to Pounds

How much 4.2 liters of each substance weighs
| Substance | Weight of 4.2 liters | One liter | Density, kg/L |
|---|---|---|---|
| Gasoline | 6.85 lbs | 1.63 lbs | 0.74 |
| Propane | 4.7 lbs | 1.12 lbs | 0.5076 |
| Water | 9.24 lbs | 2.2 lbs | 0.998 |