Semaglutide dosage calculator: mg to units
Convert your prescribed semaglutide dose from mg to units and mL on a U-100 syringe, for any vial strength.
Medically reviewed by Lindsay Short, NP-BC, Board-Certified Nurse Practitioner · last reviewed October 2026
Semaglutide dose calculator
Enter the dose your prescriber gave you and the strength printed on your vial label. The calculator converts it to units on a U-100 insulin syringe.
Example: 0.25 mg from a 2.5 mg/mL vial = 10 units (0.1 mL). Enter your own prescribed dose and vial strength above.
This converts a dose you have already been prescribed. It does not recommend a dose. Always use the concentration printed on your pharmacy label. If the number here does not match what you were told, stop and call your prescriber before injecting.
Quick answer. Units on a U-100 syringe = (prescribed dose in mg ÷ vial strength in mg/mL) × 100. 0.25 mg is 25 units at 1 mg/mL, 10 units at 2.5 mg/mL and 5 units at 5 mg/mL. 0.5 mg is 50 units at 1 mg/mL, 20 units at 2.5 mg/mL and 10 units at 5 mg/mL.
Brand Wegovy or Ozempic pen? It delivers a set dose, so there is nothing to convert. Always use the strength printed on your own vial label.
Semaglutide units chart by vial strength
Built by the clinical team at OC Weight Loss and Med Spa, a licensed medical weight loss clinic in Mission Viejo, California. The calculator's conversions for every standard dose step and the vial strengths pharmacies most often dispense. Find your prescribed dose, then your vial concentration. For the week-by-week schedule, see the semaglutide dosage chart.
| Prescribed dose | 1 mg/mL vial | 2.5 mg/mL vial | 5 mg/mL vial |
|---|---|---|---|
| 0.25 mg | 25 units (0.25 mL) | 10 units (0.1 mL) | 5 units (0.05 mL) |
| 0.5 mg | 50 units (0.5 mL) | 20 units (0.2 mL) | 10 units (0.1 mL) |
| 1 mg | 100 units (1 mL) | 40 units (0.4 mL) | 20 units (0.2 mL) |
| 1.7 mg | 170 units (1.7 mL)more than a 1 mL syringe holds | 68 units (0.68 mL) | 34 units (0.34 mL) |
| 2.4 mg | 240 units (2.4 mL)more than a 1 mL syringe holds | 96 units (0.96 mL) | 48 units (0.48 mL) |
100-unit (1 mL) syringes are usually marked every 2 units; 30- and 50-unit syringes every unit.
How the conversion works
Semaglutide is prescribed in milligrams (mg), but a vial is measured in milliliters (mL), and an insulin syringe is marked in units. On a U-100 syringe, 100 units fill 1 mL. So the conversion needs two numbers: the dose you were prescribed, and the concentration printed on your vial.
Units = dose (mg) ÷ concentration (mg/mL) × 100. For example, 0.25 mg from a 2.5 mg/mL vial is 0.1 mL, which is 10 units on a U-100 syringe.
The same dose from a different-strength vial is a different number of units, which is why a number copied from someone else's chart can be wrong for you. The FDA has received reports of patients taking five to 20 times their intended dose of compounded semaglutide after confusion between milligrams, milliliters and units.
Compounded tirzepatide and semaglutide are not FDA-approved. They are prepared by a licensed pharmacy for an individual patient, and their strength varies from pharmacy to pharmacy, which is exactly why the concentration on your own label is the number that matters. Brand pens (Zepbound, Mounjaro, Wegovy, Ozempic) deliver a fixed dose and need no conversion.
Answers before you book
How many units is 0.25 mg of semaglutide?
At 2.5 mg/mL it is 10 units (0.1 mL), at 5 mg/mL it is 5 units (0.05 mL), and at 1 mg/mL it is 25 units (0.25 mL) on a U-100 syringe. Use the strength printed on your own vial.
How many units is 0.5 mg of semaglutide?
At 2.5 mg/mL it is 20 units (0.2 mL), at 5 mg/mL it is 10 units (0.1 mL), and at 1 mg/mL it is 50 units (0.5 mL) on a U-100 syringe.
How many mg is 10 units of semaglutide?
10 units is 0.1 mL. That is 0.1 mg at 1 mg/mL, 0.25 mg at 2.5 mg/mL and 0.5 mg at 5 mg/mL. The same number of units is a different dose at each strength, which is why the strength on your label matters.
My vial label shows a total, like "5 mg/2 mL". What strength do I enter?
Divide the total milligrams by the total milliliters. 5 mg/2 mL is 2.5 mg/mL. The calculator does this for you if you choose "My label shows total mg and total mL". If the label shows only a total with no volume, ask your pharmacy for the strength in mg/mL before you draw a dose.
How do I convert semaglutide mg to units?
Divide the prescribed dose in mg by the vial concentration in mg/mL, then multiply by 100. That is the number of units on a U-100 insulin syringe.
Does this calculator tell me what dose to take?
No. It converts a dose your prescriber has already set. Any change to the dose is a decision for your prescriber.
Do Wegovy or Ozempic pens need this conversion?
No. Brand pens deliver a fixed dose. The conversion is only for vials drawn up with a syringe.
Why do small semaglutide doses read as so few units?
Semaglutide doses are small in milligrams, so on a concentrated vial they are only a few units. A lower-strength vial, or a smaller-capacity syringe with finer marks, can make them easier to measure. Ask your pharmacist.
Sources and references
- Wegovy (semaglutide) prescribing information, DailyMed
- Ozempic (semaglutide) prescribing information, DailyMed
- FDA: dosing errors associated with compounded injectable semaglutide products (alert to health care providers, compounders and patients, July 2024)
- FDA: FDA's concerns with unapproved GLP-1 drugs used for weight loss
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