Milligrams to Grams Converter

Milligrams to Grams

Convert milligrams (mg) to grams (g). Both measure mass and weight, and the conversion comes up in cooking, shipping, fitness work.

The Formula

`` grams = milligrams × 0.001 milligrams = grams × 1000 `

One milligram is 0.001 grams, and one gram is 1,000 milligrams.

Conversion Table

Milligrams	Grams
1 mg	0.001 g
2 mg	0.002 g
5 mg	0.005 g
10 mg	0.01 g
25 mg	0.025 g
50 mg	0.05 g
100 mg	0.1 g
500 mg	0.5 g
1,000 mg	1 g

The Other Direction

Grams	Milligrams
1 g	1,000 mg
2 g	2,000 mg
5 g	5,000 mg
10 g	10,000 mg
25 g	25,000 mg
50 g	50,000 mg
100 g	100,000 mg
500 g	500,000 mg
1,000 g	1,000,000 mg

What Each Unit Is

Milligrams (mg) — one thousandth of a gram. The metric unit for doses and trace quantities.

Grams (g) — one thousandth of a kilogram. The metric unit for small masses; cooking, nutrition and postage all work in grams.

A Sense of Scale

• A grain of sand is about 1 mg
• An aspirin tablet is 300–500 mg
• Nutrition labels use mg for sodium
• A paperclip is about 1 g
• A sheet of A4 is 5 g
• A tennis ball is 58 g

Precision

The factor 0.001 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.

In Code

`javascript const milligramToGram = (value) => value * 0.001; ``

Where This Conversion Comes Up

• Cooking
• Shipping
• Fitness
• Medicine
• Manufacturing

How Many Decimals Do You Need?

Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 mg with the factor truncated at each decimal place:

Decimals kept	Factor	137 mg becomes	Error
0	0	0	100.0000%
1	0	0	100.0000%
2	0	0	100.0000%
3	0.001	0.137	—
4	0.001	0.137	—

A rule that holds for any conversion: round once, at the end. Rounding the factor and then multiplying compounds the error through every subsequent calculation, while carrying full precision and rounding the final answer does not.

The right number of significant figures is set by your input, not by the converter. If you measured milligrams to three significant figures, the answer in grams is only good to three — writing more digits claims precision the measurement never had.

Other Conversions From Milligrams

The same value in every other unit this converter supports for weight:

From	To	Unit
1 mg	1.0000e-6 kg	Kilograms
1 mg	2.2046e-6 lb	Pounds
1 mg	3.5274e-5 oz	Ounces
1 mg	1.5747e-7 st	Stone
1 mg	1.0000e-9 t	Tons

Chaining conversions works — milligrams to metres to feet gives the same answer as milligrams to feet — but each step rounds, so a chain of three conversions carries three roundings. Convert directly where a direct factor exists.