⚖️ ct to mg — Carat to Milligram Converter

Convert weight and mass units — kilograms, pounds, grams, ounces, tons, carats and more.

1 unit =
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Formula 1 ct = 200 mg
Quick Answer — Formula1 ct = 200 mgMultiply carats by 200 to get milligrams.Reverse: 1 mg = 0.005 ct
UnitNameValue
0.001 ct0.2 mg
0.01 ct2 mg
0.1 ct20 mg
1 ct200 mg
5 ct1000 mg
10 ct2000 mg
50 ct10000 mg
100 ct20000 mg
1000 ct200000 mg

About Carat to Milligram Conversion

The Milligram (mg) and the Gram (g) are both units of weight & mass. Converting between them is straightforward using the formula above.

Formula: 1 ct = 200 mg

This converter uses internationally recognized conversion factors. All calculations are performed client-side in your browser — no data is sent to any server.

Worked Examples: Carat to Milligram

Paracetamol tablet dose
500 ct = 100000 mg
A standard paracetamol/acetaminophen tablet contains 500 mg of active ingredient — a common reference point in milligram-scale conversions.
Ibuprofen dose
400 ct = 80000 mg
A typical ibuprofen dose is 400 mg per tablet. Pharmacists use mg for all drug dosing to ensure precise, safe quantities.
Vitamin C daily requirement
90 ct = 18000 mg
The recommended daily intake of vitamin C is approximately 90 mg for adult men — micro-quantities that highlight why the milligram is so essential.
A grain of sand
1 ct = 200 mg
A medium grain of sand weighs roughly 1 mg — illustrating just how small a milligram really is compared to everyday objects.

Carat to Milligram Reference Table

Carat (ct)Milligram (mg)Real-world context
0.1 ct20 mg
1 ct200 mgsolitaire diamond
5 ct1000 mg
10 ct2000 mgcollector gem
100 ct20000 mg

Mental Math Tricks: Carat to Milligram

Exact integer factor
The conversion factor is exactly 200. Just multiply: n ct × 200 = result in mg.
Round factor trick
Round 200 to 200 for quick mental math. Error ≈ 0.0%.
Break factor into parts
Split 200 as 200 + 0.0000 for easier mental arithmetic.
Use ×{approx} then adjust
Multiply by 200 first, then − 0.00×n.

When to Convert Carat to Milligram

💊 Pharmacology Drug doses are specified in ct for precision. Converting between ct and mg is essential for pharmaceutical calculations and compounding.
🔬 Laboratory Work Analytical chemistry requires accurate micro-weight conversions. Carat and Milligram measurements appear in spectroscopy, chromatography, and assay procedures.
🧬 Biochemistry Enzyme activities, protein concentrations, and buffer preparations involve ct quantities that must convert accurately to mg.
🏥 Clinical Medicine Medication dosing, particularly for high-potency drugs, requires converting between ct and mg to ensure patient safety.
📊 Nutrition Science Micronutrient RDAs are expressed in ct or mg. Dietitians convert between units when planning precise supplementation protocols.
⚗️ Quality Control Industrial pharmaceutical QC tests specify tolerances in ct or mg. Batch verification requires reliable unit conversion.

Frequently Asked Questions — Carat to Milligram

1 carat (ct) equals exactly 200 milligrams (mg). Use the formula: ct × 200 = mg.

To convert carats to milligrams, multiply your value in carats by 200. For example, 5 ct × 200 = 1000 mg.

100 carats = 20000 milligrams. Calculation: 100 × 200 = 20000.

To convert milligrams back to carats, divide by 200 (or multiply by 0.005). Example: 10 mg ÷ 200 = 0.05 ct.

Yes. This converter uses the internationally recognised exact conversion factor: 1 ct = 200 mg. All calculations are performed in your browser with no rounding until display.

10 carats = 2000 milligrams. Simply multiply by 200.

Converting carats to milligrams is commonly needed for medical dosing, laboratory measurements, pharmaceutical calculations, and quality control testing where one system uses ct and another uses mg.

Understanding Carat and Milligram

Carat (ct)

The metric carat (ct) is the unit of mass used worldwide for gemstones and pearls, equal to exactly 200 milligrams (0.2 g). It is distinct from "karat" (K), the measure of gold purity (24K = 100% gold). A 1-carat diamond weighs exactly 0.2 g; the famous 45.52-carat Hope Diamond weighs approximately 9.1 g.

Milligram (mg)

The milligram (mg) is a unit of mass equal to one-thousandth of a gram (0.001 g) or one-millionth of a kilogram (10⁻⁶ kg). It is the standard unit for drug dosing in medicine and pharmacology, where precise small quantities are critical for safety and efficacy. The prefix "milli-" comes from Latin mille meaning one thousand.

History of the Carat

The word "carat" derives from Greek keration (κεράτιον), meaning carob pod. Carob seeds were believed to have remarkably uniform weight and were used as counterweights for balancing precious stones. The carat value varied across countries (0.187–0.216 g) until the Fourth General Conference on Weights and Measures standardised the metric carat at exactly 200 mg in 1907. Most countries adopted the metric carat between 1914 and 1930.

Interesting fact: The largest gem-quality diamond ever found, the Cullinan Diamond (1905), weighed 3,106.75 carats (621.35 g) before being cut into 9 major and 96 minor stones, two of which are in the British Crown Jewels.

History of the Milligram

Established as a derived unit when the metric system was formalised in the late 18th century. The milligram rose to critical importance with the growth of pharmacology in the 19th and 20th centuries, as chemists isolated active compounds and found that tiny quantities produced strong therapeutic — or toxic — effects. Modern pharmacopoeias worldwide specify drug doses in milligrams.

Interesting fact: A single grain of table salt weighs about 58 mg. One standard 325 mg aspirin tablet means that 1,000 tablets weigh only 325 grams — less than a can of soft drink.