mcg to mg Conversion Chart (and mg to mcg) for Nursing
Shows the work. Every example is computed with the formula and numbered steps. For study and exam practice, not for patient care.
Micrograms and milligrams differ by a factor of 1,000, so a slip here is a 1,000-fold dosing error. Use the chart to check your work, and the unit converter for any other amount.
Rule: 1 mg = 1,000 mcg. To go from mcg to mg, divide by 1,000 (move the decimal point 3 places left). To go from mg to mcg, multiply by 1,000.
For any other amount, use the Unit converter calculator: it shows the factor and each step.
mcg to mg
| mcg | mg |
|---|---|
| 1 | 0.001 |
| 5 | 0.005 |
| 10 | 0.01 |
| 25 | 0.025 |
| 50 | 0.05 |
| 75 | 0.075 |
| 88 | 0.088 |
| 100 | 0.1 |
| 125 | 0.125 |
| 150 | 0.15 |
| 175 | 0.175 |
| 200 | 0.2 |
| 250 | 0.25 |
| 300 | 0.3 |
| 400 | 0.4 |
| 500 | 0.5 |
| 1,000 | 1 |
mg to mcg
| mg | mcg |
|---|---|
| 0.001 | 1 |
| 0.005 | 5 |
| 0.01 | 10 |
| 0.025 | 25 |
| 0.05 | 50 |
| 0.1 | 100 |
| 0.125 | 125 |
| 0.15 | 150 |
| 0.2 | 200 |
| 0.25 | 250 |
| 0.4 | 400 |
| 0.5 | 500 |
| 1 | 1,000 |
| 2 | 2,000 |
| 5 | 5,000 |
Good to know
- Write mcg, not µg: ISMP lists µg as error-prone because it can be read as mg.
- Always write a zero before a decimal point (0.5 mg) and never a trailing zero after a whole number (5 mg, not 5.0 mg).
- Convert the order to the unit on the label before you calculate a tablet count or a volume.
Worked example
Clonidine 100 mcg PO twice daily is ordered. Available: clonidine 0.05 mg tablets.
- Desired dose
- 0.1 mg
- Have
- 0.05 mg
- Give as
- Tablets
- Scored tablet
- Yes
Formula Amount = desired ÷ have × vehicle.
- Tablets = desired dose ÷ tablet strength.
- 0.1 mg ÷ 0.05 mg = 2 tablets.
- The answer is a whole number of tablets: 2 tablets.
Answer 2 tablets
FAQ
How many mcg are in 1 mg?
1,000. A microgram is one thousandth of a milligram.
How do you convert mcg to mg?
Divide the micrograms by 1,000, which moves the decimal point three places to the left.
Why do drug labels use mcg?
Some drugs are potent in very small amounts, so their doses are written in micrograms to avoid long decimals in milligrams.
Terms on this page: mcg, Leading and trailing zeros
Sources
- List of Error-Prone Abbreviations, Symbols, and Dose Designations — Institute for Safe Medication Practices (ISMP)
- Clinical Calculations: With Applications to General and Specialty Areas (Kee, Marshall, et al.) — Elsevier
- Calculate with Confidence (Morris) — Elsevier