Free tool · no signup

Dose calculator: mg ↔ units

For vial-and-syringe users: enter your prescribed dose and vial concentration — read your U-100 syringe units, with a visual sanity check.

Draw to 20 units = 0.20 mL on a U-100 syringe

Educational arithmetic, not medical advice. Confirm every conversion with your prescriber or pharmacist — especially after a vial or concentration change. If your result is over 100 units, it will not fit a 1 mL U-100 syringe.

The formula

units = (dose mg ÷ concentration mg/mL) × 100. A U-100 syringe marks 100 units per mL, so units are simply a finer read of volume. Common example: 0.25 mg from a 2.5 mg/mL vial → 0.1 mL → 10 units.

In the app, it’s device-aware.

GLPMate’s built-in calculator knows syringes, adjustable pens (clicks) and oral tablets — and logs the exact mg with each shot, so your history and level curve stay true.

Get the app
FAQ

Dose-conversion questions

How do I convert mg to units on a U-100 syringe?

Units = (dose in mg ÷ concentration in mg/mL) × 100. Example: 0.5 mg with a 2.5 mg/mL vial → 0.5 ÷ 2.5 = 0.2 mL = 20 units on a U-100 syringe.

What does U-100 mean?

A U-100 syringe is marked so that 100 units equal exactly 1 mL. That’s why units = mL × 100 — the markings are just a finer way to read volume.

Where do I find my concentration?

On the vial label or the pharmacy paperwork, written as mg/mL (for example “semaglutide 2.5 mg/mL”). If it’s not clear, ask the pharmacy — never guess concentration.

Does this work for tirzepatide too?

Yes — the math is identical for any injectable in mg with a known mg/mL concentration. Pick your dose and concentration and read the units.

Why does GLPMate double-check with a fill visual?

Because unit errors are the most common compounding mistake. Seeing “20 units ≈ one-fifth of a 1 mL syringe” catches order-of-magnitude errors before they happen.

Is this medical advice?

No — it’s arithmetic with a safety rail. Always confirm your dose and conversion with your prescriber or pharmacist, especially when anything changes: vial, concentration or dose.

Less math. More certainty.

The in-app calculator remembers your device and concentration.