mg to mL Conversion

How to use this calculator

Enter the mass in milligrams (mg). Select the substance from the dropdown — different substances have different densities and the result will change accordingly. Press Calculate to see millilitres, litres, teaspoons, and tablespoons.

Why mg and mL are not the same unit

Milligrams (mg) measure mass — how much matter something contains. Millilitres (mL) measure volume — how much space something occupies. These are fundamentally different properties, and converting between them requires one additional piece of information: density.

Density (g/mL) tells you how much mass is packed into each unit of volume. A substance denser than water occupies less space per gram; a substance lighter than water occupies more.

Substance	Density (g/mL)	1000 mg = ? mL
Water	1.000	1.000 mL
Whole Milk	1.030	0.971 mL
Honey	1.360	0.735 mL
Maple Syrup	1.320	0.758 mL
Vegetable Oil	0.917	1.091 mL
Olive Oil	0.914	1.094 mL
Ethanol (alcohol)	0.789	1.267 mL
Glycerin	1.260	0.794 mL
Simple Syrup	1.200	0.833 mL

The formula is: mL = mg / 1000 / density

The conversion formula

The step-by-step calculation:

1. Convert milligrams to grams: g = mg / 1000
2. Divide by density: mL = g / density (g/mL)

For water, density = 1.0, so the formula simplifies to mL = mg / 1000. This is why medical dosing guides often treat 1 mg = 0.001 mL as a shortcut — it only works precisely for water or water-like solutions.

For reverse conversion (mL to mg): mg = mL x density x 1000

mg to mL conversion table for water

For quick reference, here are common milligram values converted to millilitres assuming water density (1 g/mL):

Milligrams (mg)	Grams (g)	Millilitres (mL)	Teaspoons (tsp)
100 mg	0.1 g	0.1 mL	0.020 tsp
250 mg	0.25 g	0.25 mL	0.051 tsp
500 mg	0.5 g	0.5 mL	0.101 tsp
1000 mg	1.0 g	1.0 mL	0.203 tsp
2500 mg	2.5 g	2.5 mL	0.507 tsp
5000 mg	5.0 g	5.0 mL	1.014 tsp
10000 mg	10.0 g	10.0 mL	2.029 tsp
15000 mg	15.0 g	15.0 mL	3.043 tsp

The last row (15 mL) is exactly 1 US tablespoon. Note that 5 mL = 1 teaspoon, which is the standard medical measuring reference.

Using mg to mL in cooking

In cooking, you rarely encounter milligrams as a measuring unit — most kitchen scales read in grams. But mg conversions appear in several practical contexts:

Nutritional labelling: Vitamin and mineral content is listed in mg on food labels. If you want to know what volume of olive oil delivers 500 mg of fat, use the density conversion.

Liquid flavourings: Vanilla extract, food colouring, and concentrated flavour drops are sometimes sold with mg dosing instructions. A common vanilla extract density is around 1.05 g/mL, so 1000 mg of extract = 0.952 mL.

Syrups and sweeteners: Honey (1.36 g/mL) and maple syrup (1.32 g/mL) are significantly denser than water. 1000 mg of honey = 0.735 mL, not 1 mL. Knowing this helps when scaling recipes that mix weight and volume measurements.

Alcohol in recipes: Ethanol has a density of 0.789 g/mL. 100 mg of pure alcohol = 0.127 mL. At typical wine strength (13.5% ABV), 100 mL of wine contains about 10.7 mL of ethanol = 8,440 mg of pure alcohol.

mg to mL in medicine and supplements

Medical dosing almost always uses mg for drug quantities and mL for liquid volumes. Understanding the relationship prevents dangerous dosing errors.

The concentration label is critical. A bottle labelled “250 mg / 5 mL” means every 5 mL contains 250 mg of active ingredient. The effective density for dosing purposes is 250 / 5 = 50 mg/mL. To give a 500 mg dose: 500 / 50 = 10 mL.

Do not assume 1 mg = 0.001 mL unless the substance is specifically water or a water-based solution at 1 mg/mL concentration. Many syrups, suspensions, and concentrated solutions are at very different concentrations.

Standard liquid medicine volumes:

• 2.5 mL = half a teaspoon (common infant dose)
• 5 mL = 1 teaspoon (most common adult liquid dose unit)
• 10 mL = 2 teaspoons
• 15 mL = 1 tablespoon

Always use the measuring device that came with the medication rather than household spoons, which vary significantly in actual volume.

mg to mL for oils and fats

Cooking oils are routinely measured in both tablespoons (volume) and grams or milligrams (weight). The conversion uses the specific gravity of each oil:

Oil	Density (g/mL)	1 tbsp (14.787 mL) = ? mg
Olive oil	0.914	13,555 mg
Vegetable oil	0.917	13,599 mg
Coconut oil	0.925	13,698 mg
Sunflower oil	0.920	13,624 mg
Sesame oil	0.919	13,609 mg
Canola oil	0.922	13,653 mg

When a recipe says “14 g of olive oil,” that is 14,000 mg. At 0.914 g/mL: 14,000 / 1000 / 0.914 = 15.32 mL, just over 1 tablespoon.

Honey and syrup conversions

Honey and syrups are the densest common kitchen liquids. Their high viscosity and density make volume measurements less accurate, so bakers and pastry chefs prefer to weigh them.

Honey: density 1.36 g/mL (varies with moisture content from 1.33 to 1.45 g/mL).

• 1 tablespoon (14.787 mL) of honey = 20.1 g = 20,100 mg
• 500 mg of honey = 0.368 mL, about 1/13 of a teaspoon

Maple syrup: density 1.32 g/mL (Grade A amber).

• 1 tablespoon of maple syrup = 19.5 g = 19,520 mg
• 500 mg of maple syrup = 0.379 mL

Simple syrup (1:1 sugar to water): density approximately 1.2 g/mL.

• 1 tablespoon = 17.7 g = 17,700 mg

Because honey and maple syrup weigh substantially more per millilitre than water, substituting one for the other in a recipe by volume changes the total weight. A recipe calling for 50 mL of honey (68 g) cannot be substituted with 50 mL of simple syrup (60 g) without adjusting the liquid balance.

Glycerin and alcohol conversions

Glycerin and alcohol are common in both cooking and personal care applications.

Glycerin (glycerol): density 1.26 g/mL. Used in baking to retain moisture and in confectionery. 1000 mg of glycerin = 0.794 mL. It is noticeably heavier than water and slightly viscous.

Ethanol (food-grade alcohol, vodka base): density 0.789 g/mL. Used in vanilla extract, liqueur, and infusions. 1000 mg of pure ethanol = 1.267 mL. Spirits contain water, so the actual density varies: 80-proof vodka (40% ABV) has a density of approximately 0.95 g/mL.

Isopropyl alcohol: density 0.791 g/mL. Not for consumption but common in health and cleaning contexts. 1000 mg = 1.265 mL.