mg to mcg Calculator
1 mg equals 1,000 mcg. To convert mg to mcg, multiply by 1,000; to convert mcg to mg, divide by 1,000. Enter a value below to convert it exactly, in either direction.
mg to mcg Calculator
mg ↔ mcg calculator
Enter a value to convert.
Arithmetic only: it never suggests or assesses an amount. Nothing you type leaves your browser.
mg to mcg conversion table
| mg | mcg |
|---|---|
| 0.1 mg | 100 mcg |
| 0.25 mg | 250 mcg |
| 0.5 mg | 500 mcg |
| 1 mg | 1,000 mcg |
| 2.5 mg | 2,500 mcg |
| 5 mg | 5,000 mcg |
| 10 mg | 10,000 mcg |
mcg (also written µg) is a microgram, one millionth of a gram. mg is a milligram, one thousandth of a gram.
mg to mL is a different question
mg and mcg are both mass, so they convert with a fixed factor. mL is volume: “how many mL is 2.5 mg” depends on the concentration of the solution. Use the mcg to mL calculator or the reconstitution calculator for that.
Converting to IU
IU (international units) measure activity, and each substance has its own IU-per-mg factor, set by its reference standard. There is no universal conversion, so the calculator asks for the factor from the product’s label or data sheet and never fills one in.
Frequently asked questions
How many mcg are in 1 mg?
1,000 mcg.
How do I convert mg to mcg?
Multiply by 1,000. 2.5 mg × 1,000 = 2,500 mcg.
How do I convert mg to mL?
You need the concentration: mL = mg ÷ concentration in mg/mL. At 5 mg/mL, 2.5 mg is 0.5 mL.
How many units is 2.5 mg on an insulin syringe?
It depends on the concentration. At 5 mg/mL, 2.5 mg is 0.5 mL, which is 50 units on a U-100 syringe; at 10 mg/mL it is 25 units.
Related calculators and guides
- CalculatorMcg to mL calculatorConvert mcg to mL using your solution’s concentration, with U-100 syringe units and the nearest marking.
- CalculatorReconstitution calculatorWork out concentration after adding bacteriostatic water, then the mL and U-100 units for any amount.
- GuideInsulin Syringe Units Explained1 mL is 100 units on a U-100 syringe.
- CalculatorConcentration calculatorCalculate a solution’s concentration in mg/mL and mcg/mL, the amount in 0.1 mL or one U-100 unit, and how to dilute it with C1V1 = C2V2.
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Last reviewed · How the calculations work