How To Convert Milligram to Carats
Formula: carats = milligrams ÷ 200
Example: Convert 350 milligrams to carats.
350 ÷ 200 = 1.75 carats
To do this by hand, remember that 1 carat is exactly 200 milligrams. So you are finding how many groups of 200 mg fit into your milligram value. If the number is not a perfect 200, you will get a decimal carat value. You can also divide by 2, then move the decimal two places left, because ÷200 is the same as ÷2 and then ÷100.
Quick Answer
1 Milligram = 0.005 Carats
- 10 milligrams = 0.05 carats
- 200 milligrams = 1 carat
- 750 milligrams = 3.75 carats
Conversion Formula
carats = milligrams / 200 milligrams = carats * 200
This means you divide by 200 because one carat is defined as 200 milligrams. So every 200 mg adds exactly 1 carat. Smaller milligram amounts become a decimal part of a carat.
- Write down the milligram value.
- Divide it by 200.
- The result is the weight in carats.
Milligram
A milligram is a metric unit of mass equal to one thousandth of a gram. You will often see it written as mg, and you can read more about milligram.
The milligram comes from the metric system, built around powers of ten to make measuring easier. It became widely used as science, medicine, and precise weighing tools became common.
- Measuring medicine doses
- Lab and chemistry measurements
- Nutrition facts for vitamins and minerals
- Weighing small powders and supplements
- Precision weighing in research
Carat
A carat is a unit of mass used for gemstones, defined as exactly 200 milligrams. The symbol is ct, and you can read more about carat.
Historically, carat weights were linked to carob seeds used in old trading. Today, the metric carat is a fixed standard so gem weights are the same worldwide.
- Weighing diamonds and colored gemstones
- Jewelry pricing and appraisal
- Gemstone trading and wholesale parcels
- Stone setting and design specifications
- Gem lab reports and certificates
Is this Conversion of Milligram To Carats Accurate?
Yes. This conversion is exact because the metric carat is defined as 200 milligrams with no rounding. Our converter uses this fixed definition used by gem labs, jewelers, textbooks, and international standards bodies, so the results are reliable for trade, study, and daily use. For how we verify and keep values consistent, read our standards note here, accuracy standards.
Real Life Examples
Milligram to carats is common when you have a milligram reading from a small scale, but you need the gemstone weight in carats.
- A tiny diamond melee stone: A stone weighs 20 milligrams. 20 ÷ 200 = 0.10 carats.
- Converting a scale reading for a loose diamond: Your scale shows 250 milligrams. 250 ÷ 200 = 1.25 carats.
- Comparing two gemstones: Stone A is 180 milligrams and Stone B is 220 milligrams. A is 180 ÷ 200 = 0.90 carats, B is 220 ÷ 200 = 1.10 carats.
- Matching a lab report: A report lists 0.75 carats, but your scale is in mg. 0.75 × 200 = 150 milligrams.
- Buying a parcel of stones: A parcel weighs 1,000 milligrams total. 1,000 ÷ 200 = 5 carats total weight.
- Checking “points” quickly: A jeweler says a stone is 50 points (0.50 carats). In mg that is 0.50 × 200 = 100 milligrams.
- Planning a custom setting: A design needs a 2.5 carat center stone. In milligrams that target is 2.5 × 200 = 500 milligrams.
Quick Tips
- Remember the key fact, 1 carat = 200 mg.
- To go from mg to carats, divide by 200.
- To go from carats to mg, multiply by 200.
- 100 mg is always 0.5 carats, because it is half of 200 mg.
- 50 mg is 0.25 carats, because it is one quarter of 200 mg.
- For a fast mental method, divide mg by 2, then move the decimal two places left.