Everything you need to know about measuring milligrams, micrograms, and grams, from terms and origin to how many milligrams are in a gram.

How many mg in a gram?
Grams and milligrams are a metric unit of measurement, meaning they all divide neatly into each other!
- There are 1,000 milligrams in 1 gram.
- There are 1,000 micrograms in 1 milligram.
- There are 1,000,000 micrograms in 1 gram.
How many grams in a milligram? Well just the inverse! 1/1000th of a gram. How many grams in a microgram? 1/millionth of a gram. (Similarly, if you’re wondering how many milliLITERS are in a LITER, the answer is also 1000!)
What Is A Gram (g)?
The gram was introduced in France shortly after the French Revolution. The word gramme was adopted by the French in a 1795 decree revising the metric system and defining the gram as the weight of one cubic centimeter of water. Republican France wanted to rid itself of all the “old ways”. This went well beyond beheading the king and queen. Standardizing measurements for trade was one such change in France, and it caught on. Today only three nations don’t use the metric system – the USA, Liberia, and Myanmar. To be fair the USA does use metric weights in most scientific and engineering applications, and you will increasingly find recipe ingredients measured in grams.
What Is A Milligram (mg)?
Simplistically, a milligram is 1/1000th of a gram. Like so many of our measurements, the word “Milli” comes from Ancient Rome. A milli was a thousand, thus its modern use to denote 1 thousandth part of something. Now with that, you are all set for Jeopardy. Seriously though, as recipes increasingly adopt the metric system understanding grams and milligrams takes on increased importance particularly when dealing with small ingredient quantities like spices. Our nutrition information today is also largely in metrics. So, if you want to track your macros, you have to do that in grams. Similarly, if you are concerned about your calcium or Vitamin C intake, these are all measured in milligrams. Let’s face it, ounces of calcium would be a little awkward.
What Is A Microgram (mcg)?
Microgram is 1/1000th of a milligram or 1 millionth of a gram. The prefix “micro” comes from Ancient Greek. Micro simply meant “small”. One millionth of anything is certainly small, so the term was adopted. Why should I care? Well, there isn’t a lot in everyday life measured in micrograms. Certainly, no recipe will ask you to use mcg. It is, however, a unit of measure for some vitamins and minerals. Vitamins B12 and K are measured in micrograms, as are some minerals.
Quick Gram Conversions
1 million micrograms | = | 1 gram |
1 thousand milligrams | = | 1 gram |
1 gram | = | 1/1000 of a kilogram |
10 grams | = | 1 centigram |
100 grams | = | 1 hectogram |
1000 grams | = | 1 kilogram |
1,000,000 grams | = | 1 metric ton |
So to wrap up, 1 gram equals how many milligrams? 1000!
Linda zapach says
So….I have read that if one is trying to cut down high cholesterol numbers for better health, less than 11 grams of cholesterol should be consumed per day. Does that mean that I can consume 11,000 mgs of cholesterol in my food per day and I would be within the 11 grams that should only be consumed per day?
Sarah Bond says
Your math is right but I don’t think that number is. The typical recommendation is to consume less than 200 mg of cholesterol per day for those with high cholesterol.
Gina Davis says
Very helpful information ty
Charles says
This was an excellent article for someone not accustomed to utilizing metric measurements. Thank you for your thoroughness.
Linda A Smyth says
300000 iud of vitamin c would equal about how many grams of Vitamin C.?
Sarah Bond says
I tried researching this but I’m honestly not sure, Linda! It seems like most of the calculations for this are for fat-soluble vitamins, but vitamin C is water soluble. Not sure if that has anything to do with it?