Tirzepatide and semaglutide units calculator (mg to units)

To convert a tirzepatide or semaglutide dose from mg to units, divide the dose by the concentration printed on the vial and multiply by 100. Units = mg ÷ (mg/mL) × 100. At 10 mg/mL, a 2.5 mg dose is 0.25 mL, which is 25 units on a U-100 syringe. The concentration differs between pharmacies, so always use the one on your own label.

The formula

Volume: dose (mg) ÷ concentration (mg/mL) = mL
Units: volume (mL) × 100 = units on a U-100 syringe
Units to mg: units ÷ 100 × concentration (mg/mL) = mg

Worked example

The vial label says 10 mg/mL and your prescription says 2.5 mg.
2.5 ÷ 10 = 0.25 mL.
0.25 × 100 = 25 units on a U-100 syringe.
With a 5 mg/mL vial the same 2.5 mg dose would be 50 units, which is why the label matters.

mg to units chart

Units on a U-100 syringe for a dose in mg, by vial concentration
Concentration	0.25 mg	0.5 mg	1 mg	2.5 mg	5 mg
2.5 mg/mL	10 units	20 units	40 units	100 units	Over 100
5 mg/mL	5 units	10 units	20 units	50 units	100 units
10 mg/mL	2.5 units	5 units	10 units	25 units	50 units
20 mg/mL	1.25 units	2.5 units	5 units	12.5 units	25 units

Common questions

How many units is 2.5 mg of tirzepatide?

It depends on the concentration on your vial. At 10 mg/mL it is 25 units on a U-100 syringe. At 5 mg/mL it is 50 units, and at 20 mg/mL it is 12.5 units.

How many units is 0.25 mg of semaglutide?

At 2.5 mg/mL it is 10 units on a U-100 syringe. At 5 mg/mL it is 5 units. Check the concentration on your label, because compounded vials vary.

Do I need this for a brand-name pen?

No. Pens such as Ozempic, Wegovy, Mounjaro and Zepbound deliver a pre-set dose and need no conversion. This calculator is for vials used with a syringe.

Why is the same dose a different number of units on another vial?

Units measure volume, not amount. A more concentrated vial holds the same dose in less liquid, so the number of units is smaller. Never carry a units number over from one vial to another without checking the concentration.

Does this calculator tell me what dose to take?

No. Your dose is set by your prescriber. This converts that dose into a volume. If the result does not match the instructions from your pharmacy, stop and ask them before injecting.

Other calculators

Keep the numbers with your log

Record each vial's strength and status in PepVault, next to every dose you log. Free for Android, iPhone, iPad and Mac.

For Android, iPhone, iPad and Mac. On the App Store the app is listed as PeptideMate.