Convert kg to mg
Convert kg to mg instantly. 1 kg = 1,000,000 mg. Formula, worked examples and a quick reference table.
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One kilogram equals 1,000,000 milligrams. To convert any number of kilograms to milligrams, multiply by 1,000,000.
The converter above works in both directions and updates as you type. Below you will find the formula, a worked example and a reference table of common values.
Weight and mass conversions matter most in three places: shipping, where a rate band can turn on a single kilogram; cooking, where recipes cross between metric grams and imperial ounces; and personal weight, where Britain and Ireland use stones, the United States uses pounds, and everywhere else uses kilograms. Strictly these are mass units rather than weight units, and the distinction only bites in physics, where weight is a force measured in newtons.
kg to mg formula
To go the other way, use kilogram = milligram ÷ 1,000,000.
About these units
Since 2019 the kilogram has been defined by the Planck constant rather than a metal cylinder in Paris, making it reproducible in any properly equipped laboratory.
The milligram is a thousandth of a gram, and the standard unit for medicine doses and nutrition labels, where the quantities are far too small for grams to be readable.
Kilogram is also written kilogramme, kilogrammes, kilograms, kilos, kilo and kgs. Milligram is also written milligramme and milligrams.
Sources
kg to mg conversion table
| Kilogram | Milligram |
|---|---|
| 1 kg | 1,000,000 mg |
| 2 kg | 2,000,000 mg |
| 3 kg | 3,000,000 mg |
| 5 kg | 5,000,000 mg |
| 10 kg | 10,000,000 mg |
| 20 kg | 20,000,000 mg |
| 25 kg | 25,000,000 mg |
| 50 kg | 50,000,000 mg |
| 100 kg | 100,000,000 mg |
| 250 kg | 250,000,000 mg |
| 500 kg | 500,000,000 mg |
| 1,000 kg | 1,000,000,000 mg |
Frequently asked questions
How many milligrams are in a kilogram? +
There are 1,000,000 milligrams in one kilogram.
What is 10 kg in mg? +
10 kg equals 10,000,000 mg. Multiply 10 by 1,000,000.
How do I convert milligram back to kilogram? +
Use kilogram = milligram ÷ 1,000,000. The converter above handles both directions, or see our dedicated mg to kg page.
How accurate is this kilogram to milligram conversion? +
The factor used is 1,000,000, carried at full double precision. Where a unit has an exact legal definition the factor is exact rather than approximate. Rounding is applied only to the displayed result, so the answer is never a calculation done on an already-rounded number.
Is there a quick way to estimate kg to mg in my head? +
The factor is exactly 1,000,000, which is short enough to apply directly without an approximation.