How it's calculated
kg = mL × ρ ÷ 1,000
mL = volume, ρ = density (g/mL), kg = mass. Reverse mL = kg × 1,000 ÷ ρ. Water ρ = 1 g/mL.
Worked examples
| Substance | 1000 mL weighs | Note |
|---|---|---|
| Water | 1.00 kg | Baseline |
| Gasoline | 0.748 kg | Lighter |
| Honey | 1.42 kg | Heavier |
| Milk | 1.03 kg | Slightly heavier |
Common questions
Does 1000 mL always equal 1 kg?
Only for water. Other substances are lighter or heavier per milliliter, so a liter of them weighs more or less than a kilogram.
Where do these densities come from?
They come from NIST, USDA, and BIPM reference data measured at standard conditions.