Why you can't convert grams to milliliters with one universal number
Grams measure mass. Milliliters measure volume. The only reason "1 mL = 1 g" feels like a safe shortcut is that it happens to be true for water — it isn't true for almost anything else in the kitchen. 100 mL of honey weighs 142 g, while 100 mL of flour weighs just 53 g — nearly a 3× difference for the exact same volume, because honey packs far more mass into the same space than flour's light, air-filled structure does. The conversion factor that bridges the two is density (grams per milliliter), and it's different for every ingredient.
Where these density figures come from, and their real limits
The values built into this converter are standard kitchen reference densities, cross-checked against independent culinary sources rather than pulled from a single chart:
| Ingredient | Density | 100 mL weighs |
|---|---|---|
| Water | 1.00 g/mL | 100 g |
| Milk | 1.03 g/mL | 103 g |
| Flour, all-purpose | 0.53 g/mL | 53 g |
| Sugar, granulated | 0.85 g/mL | 85 g |
| Honey | 1.42 g/mL | 142 g |
| Vegetable oil | 0.92 g/mL | 92 g |
| Butter, melted | 0.96 g/mL | 96 g |
These are useful planning figures, not a guarantee for your specific brand, batch, or measuring technique. Flour varies the most of anything on this list — sifted, spooned, and scooped-and-packed flour can differ from each other by 20–30% or more in weight for the identical cup or milliliter measurement, since how much air gets packed in along with the flour depends entirely on handling. Butter listed here is melted butter specifically, since that's the form it's actually flowable and measurable by volume in the first place — solid butter is denser and is usually measured by weight, by the stick, or by its printed markings instead. For anything where precision genuinely matters (most of all baking), weighing the ingredient directly on a kitchen scale will always be more reliable than converting from a volume measurement.
Physical factors that alter real-world ingredient densities
While standard density tables give a reliable baseline, physical kitchen conditions introduce variable margins:
- Aeration & Compaction: Dry powders like cocoa powder, powdered sugar, and all-purpose flour settle over time in the pantry. A cup scooped straight from a packed bag holds significantly more mass than a cup fluff-spooned into a measuring vessel.
- Temperature Fluctuations: Viscous liquids like honey, molasses, and oils expand slightly when heated and contract when cold, subtly altering their g/mL density ratio.
- Humidity & Moisture Absorption: Ingredients like salt, white sugar, and flour absorb ambient moisture in humid environments, increasing their weight-to-volume density.
A note on units & international recipe scaling
Milliliters (mL) and liters (L) are standard metric units, so they mean the same thing everywhere. Because this converter works directly with mL and L, the results are consistent regardless of where a recipe comes from. If you're converting a recipe between metric and US kitchen measurements, you can also use our Cups to mL converter for cup-to-milliliter conversions.
Frequently asked questions
How many grams is 100 mL of flour?
About 53 g, using a standard all-purpose flour density of 0.53 g/mL. This varies by how the flour is measured — sifted flour weighs noticeably less than packed flour for the same volume.
How many grams is 100 mL of honey?
About 142 g, since honey is considerably denser than water at roughly 1.42 g/mL.
Can I convert an ingredient that isn't in the list?
Yes — choose "Custom Density" and enter the ingredient's known density in g/mL. If you know that a specific weight fills a specific volume (say, 62 g fills 50 mL), divide weight by volume to get the density (1.24 g/mL in that example).
Why do professional bakers prefer grams over milliliters?
Measuring mass (grams) eliminates errors caused by air pockets, packing density, and uneven cup fill lines. Grams guarantee exact ratios regardless of ingredient handling.