Tip: For water, use density = 1 g/mL. Results may vary with temperature and purity.
How to convert mL to kg correctly
Converting milliliters (mL) to kilograms (kg) is not a direct unit conversion because mL measures volume and kg measures mass. To convert between them, you must know the substance’s density.
That’s exactly what the calculator above does: it takes your volume in mL, applies density, and gives you mass in kg.
Conversion formula
If your density is in kg/m³, it is first converted to g/mL by dividing by 1000.
Why density matters
1,000 mL of two different liquids can have very different masses:
- Water (1.00 g/mL): 1,000 mL = 1.00 kg
- Olive oil (0.92 g/mL): 1,000 mL = 0.92 kg
- Honey (1.42 g/mL): 1,000 mL = 1.42 kg
Same volume, different mass. That is why any reliable mL to kg conversion needs density.
Common density reference table
| Substance | Approx. Density (g/mL) | 1,000 mL in kg |
|---|---|---|
| Water | 1.00 | 1.00 kg |
| Milk | 1.03 | 1.03 kg |
| Olive oil | 0.92 | 0.92 kg |
| Honey | 1.42 | 1.42 kg |
| Gasoline | 0.74 | 0.74 kg |
| Ethanol | 0.79 | 0.79 kg |
Worked examples
Example 1: 500 mL of water to kg
Use density = 1.00 g/mL.
kg = (500 × 1.00) ÷ 1000 = 0.50 kg
Example 2: 250 mL of honey to kg
Use density = 1.42 g/mL.
kg = (250 × 1.42) ÷ 1000 = 0.355 kg
Example 3: 2,000 mL of olive oil to kg
Use density = 0.92 g/mL.
kg = (2000 × 0.92) ÷ 1000 = 1.84 kg
mL to kg for water (quick chart)
| mL | kg (water) |
|---|---|
| 100 mL | 0.10 kg |
| 250 mL | 0.25 kg |
| 500 mL | 0.50 kg |
| 750 mL | 0.75 kg |
| 1,000 mL | 1.00 kg |
| 1,500 mL | 1.50 kg |
| 2,000 mL | 2.00 kg |
Frequently asked questions
Is 1 mL always equal to 1 gram?
No. That is only true for water (approximately, near room temperature). Other liquids are lighter or heavier.
Can I convert mL to kg without density?
Not accurately. You need the density of the specific substance you are measuring.
Are g/mL and kg/L the same?
Yes. Numerically, 1 g/mL = 1 kg/L.
Final tip
If precision matters for science, manufacturing, or recipes at scale, always use density values measured at the correct temperature. For everyday estimates, the calculator and density presets above are usually enough.