Grams to millilitres always needs a density
Grams measure mass; millilitres measure volume. The bridge between them is density, the mass packed into each millilitre. Water is 1 g/ml, so 100 g is 100 ml. Everything else is denser or lighter, so the two numbers separate. To go the other way, multiply: grams = millilitres × density.
Density is why 100 g takes a different volume each time
Same 100 g, very different volumes. Dense honey occupies little space; airy flour occupies a lot.
The same mass spans 70 to 169 ml depending on the ingredient, so treating grams and millilitres as interchangeable can leave a recipe off by half.
Density of common ingredients
| Substance | Density (g/ml) | 100 g equals |
|---|---|---|
| Water | 1.00 | 100 ml |
| Milk (whole) | 1.03 | 97 ml |
| Vegetable oil | 0.92 | 109 ml |
| Butter | 0.91 | 110 ml |
| Honey | 1.42 | 70 ml |
| Granulated sugar | 0.79 | 127 ml |
| Brown sugar (packed) | 0.83 | 120 ml |
| All-purpose flour | 0.59 | 169 ml |
| Cocoa powder | 0.56 | 179 ml |
| Salt (fine) | 1.20 | 83 ml |
Powders vary most: flour scooped and packed can read 0.65 g/ml against 0.55 g/ml lightly spooned, a 20% swing. Weigh when accuracy matters.
Getting it right
- Liquids cluster near 1. Milk, vinegar and yogurt sit within a few percent of water, so ml and g are close but not identical.
- Temperature is minor. Density shifts under about 2% across normal kitchen temperatures. Ignore it for cooking; standardise at 20°C for lab work.
- cc = ml. A cubic centimetre is the same volume as a millilitre, so any density in g/ml also works in g/cc.
Common questions
Is 100 g the same as 100 ml?
Only for water, which has a density of 1 g/ml. For anything else you divide the grams by the density: 100 g of flour is about 169 ml because flour is much less dense, and 100 g of honey is only about 70 ml.
How do I convert grams to millilitres without a density?
You cannot. Grams measure mass and millilitres measure volume, so you need the density of the specific substance to link them. Water is the one case where the numbers happen to match.
How many ml is 200 g of flour?
About 338 ml, or roughly 1.4 US cups, using a flour density near 0.59 g/ml. Packing changes this, so weigh flour when you can rather than measuring by volume.
