Grams to Milligrams Converter

Convert grams to milligrams instantly, and milligrams back to grams. Based on the exact 1 g = 1000 mg SI definition.

Independently verified for accuracy

Calculator by Toolsloft ↗
Result
1000 Milligrams (mg)
Conversion
1 Grams (g) = 1000 Milligrams (mg)

Convert grams to milligrams, and milligrams back to grams. Nutrition labels and dosing charts often need a gram figure broken down into milligrams. Enter the value and read the answer.

How this is calculated

One gram is exactly 1000 milligrams, so grams are multiplied by 1000 to get milligrams and milligrams are divided by 1000 to get grams. These are SI prefixes with fixed powers of ten, and results are shown to six decimal places.

How to use

  1. Enter the number of grams.
  2. Keep the direction on grams to milligrams, or press Swap units for milligrams to grams.
  3. Read the result in milligrams.

Examples

  • 1 grams: 1 g = 1000 mg
  • 0.5 g: 0.5 g = 500 mg
  • Reverse: 1000 mg = 1 g

FAQ

How many milligrams are in a gram?
Exactly 1000 milligrams, because milli means one thousandth in the SI system.
How do I convert grams to milligrams?
Multiply the number of grams by 1000. For example, 2.5 grams is 2500 milligrams.

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