Converter

Drug Unit Converter

The drug unit converter converts between the metric units used in drug prescriptions and pharmacology: grams (g), milligrams (mg), micrograms (mcg/μg), and nanograms (ng). Unit confusion — particularly between milligrams and micrograms — is one of the most common and dangerous sources of medication errors, representing a 1000-fold dosing difference. Use this converter to verify unit conversions before drawing up any medication.

Converted Value
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Quick Reference

FromToMultiply by
gmg× 1,000
mgmcg× 1,000
mcgng× 1,000
mgg÷ 1,000
mcgmg÷ 1,000
kglb× 2.20462
lbkg÷ 2.20462

Related Calculators

Frequently Asked Questions

How many mcg (micrograms) are in 1 mg (milligram)?

There are 1,000 micrograms (mcg) in 1 milligram (mg). This is one of the most important conversions in nursing — mistaking mg for mcg results in a 1000-fold overdose. Always double-check the unit on the drug label before administration.

How many mg are in 1 gram?

There are 1,000 milligrams (mg) in 1 gram (g). The full metric chain is: 1 g = 1,000 mg = 1,000,000 mcg = 1,000,000,000 ng.

📖 Formula source: BIPM. The International System of Units (SI), 9th edition. 2019.
Double-check unit conversions before drug preparation. Errors of 1000-fold (mg vs mcg) are a common source of medication errors.