【How-to】How big is a milligram

Understanding the definition of the prefix can help you remember the difference between grams and milligrams. Since “milli” means one-thousandth, a milligram is 1/1,000 of a gram. Multiply the number of grams (g) by 1,000 to get milligrams (mg). … So, 75 grams (g) is equal to 75,000 milligrams (mg).