mg to mL Calculator

Use the mg to mL calculator to convert between milligrams and milliliters with ease.

Density decides the answer — a cup of flour weighs far less than a cup of honey.
g/ml
Used when “Custom density” is selected.
Clear
Result0.001 ml1 mg of water
Density used1 g/ml1,000 kg/m³
1 mg of water0.001 ml

1 mg of…

SubstanceDensity1 mg weighs / measures
Water1 g/ml0.001 ml
Milk (whole)1.03 g/ml0.00097087 ml
Flour (all-purpose)0.529 g/ml0.00189036 ml
Sugar (granulated)0.845 g/ml0.00118343 ml
Butter0.911 g/ml0.00109769 ml
Vegetable oil0.92 g/ml0.00108696 ml
Honey1.42 g/ml0.00070423 ml
Table salt1.217 g/ml0.00082169 ml
Rice (uncooked)0.85 g/ml0.00117647 ml

Why milligram to milliliter needs a substance

Milligrams measure weight and milliliters measure volume, so there is no single conversion factor between them. What bridges the two is density — how much a given volume of that particular substance weighs:

volume = mass ÷ density

Water is the easy case: it is almost exactly 1 g/ml, so 1 ml of water weighs 1 g and the numbers look identical. Nothing else behaves that way — flour is about half as dense, and honey is nearly half again as dense.

Using this for recipes

Pick the ingredient from the list and the conversion uses a typical density for it. Dry ingredients are the least predictable: scooping flour straight from the bag can pack in 20% more than spooning it in gently, which is exactly why baking recipes prefer weights. If you have a density from a supplier or a label, choose Custom density and enter it.

Densities here are typical values for guidance. For anything where precision matters, weigh it.