mcg to mg Calculator — Microgram to Milligram Converter
Convert micrograms (mcg) to milligrams (mg) instantly. Essential for calculating GLP-1 doses like Semaglutide, Tirzepatide and Retatrutide, as well as all research peptides. Simply enter your value and get the instant conversion — or use the reference tables below for common doses.
1 mg = 1,000 mcg | 1 mcg = 0.001 mg
Common peptide doses — click to convert:
Common Peptide mcg to mg Conversions
Common peptide dose conversions from micrograms to milligrams, with typical use cases for each dose range.
| mcg | mg |
|---|---|
| 100 mcg | 0.1 mg |
| 200 mcg | 0.2 mg |
| 250 mcg | 0.25 mg |
| 300 mcg | 0.3 mg |
| 500 mcg | 0.5 mg |
| 1,000 mcg | 1 mg |
| 2,000 mcg | 2 mg |
| 2,400 mcg | 2.4 mg |
| 2,500 mcg | 2.5 mg |
| 5,000 mcg | 5 mg |
| 10,000 mcg | 10 mg |
| 15,000 mcg | 15 mg |
GLP-1 Dose Reference Chart
Common GLP-1 pen doses converted between mg and mcg, with the clinical context for each dose level.
| Dose (mg) | Dose (mcg) | Common Use |
|---|---|---|
| 0.25 mg | 250 mcg | Semaglutide starting dose |
| 0.5 mg | 500 mcg | Semaglutide maintenance |
| 1 mg | 1,000 mcg | Semaglutide weekly dose |
| 1.7 mg | 1,700 mcg | Semaglutide higher dose |
| 2.4 mg | 2,400 mcg | Semaglutide max dose / Cagrilintide |
| 2.5 mg | 2,500 mcg | Tirzepatide starting dose |
| 5 mg | 5,000 mcg | Tirzepatide maintenance |
| 7.5 mg | 7,500 mcg | Tirzepatide mid dose |
| 10 mg | 10,000 mcg | Tirzepatide higher dose |
| 12.5 mg | 12,500 mcg | Tirzepatide higher dose |
| 15 mg | 15,000 mcg | Tirzepatide max dose |
| 2 mg | 2,000 mcg | Retatrutide / general peptides |
| 5 mg | 5,000 mcg | Common vial size |
| 10 mg | 10,000 mcg | Common vial size |
Why mcg and mg Both Matter for Peptide Dosing
Peptide dosing involves two units that are easy to confuse: micrograms (mcg) and milligrams (mg). Vial sizes are almost always labeled in milligrams — a BPC-157 vial is "5 mg", a semaglutide vial is "5 mg", a tirzepatide vial is "10 mg". But dosing instructions and clinical literature typically express doses in micrograms — "250 mcg of BPC-157 twice daily", "500 mcg of semaglutide weekly to start".
The conversion is straightforward: 1 mg = 1,000 mcg. But when you are calculating injection volumes, preparing multiple vials, or scaling doses, it is easy to make a tenfold error by losing track of which unit you are working in. A dose of 250 mcg is 0.25 mg — if you accidentally treat it as 250 mg, the error is a factor of 1,000.
For GLP-1 agonists, the unit confusion can be especially consequential. Semaglutide doses ramp from 0.25 mg (250 mcg) to 2.4 mg (2,400 mcg) per week for weight management. Tirzepatide doses range from 2.5 mg (2,500 mcg) to 15 mg (15,000 mcg). Having a reliable converter on hand prevents costly mistakes at every step.
Bookmark this page and use it every time you switch between package labeling (mg) and dosing protocols (mcg). The bidirectional calculator above updates in real time — type either value and the other fills in immediately, eliminating any chance of arithmetic error.