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This semaglutide peptide calculator converts the milligram dose on your prescription into units on a U-100 insulin syringe. Semaglutide doses are small, often a fraction of a milligram, so a few units either way makes a real difference. Let the calculator do the arithmetic, then double-check it against your pharmacy's instructions.
Step 1: Choose your syringe. A 0.3 mL (30 unit) syringe is usually easiest to read for small doses, since it's typically marked at every unit. Pick whichever size you actually have.
Step 2: Enter your vial size. Use the milligrams printed on your vial label. Tap Custom if your size isn't listed.
Step 3: Enter the diluent volume. This is how much bacteriostatic water (or other diluent) was added. If your pharmacy sent the vial pre-mixed, match the concentration on the label: a vial labelled 2.5 mg/mL is the same as 5 mg in 2 mL.
Step 4: Enter your prescribed dose in mg. Presets are shortcuts, not recommendations. Use the exact number your prescriber gave you.
With the defaults shown, 0.25 mg out of a 5 mg vial mixed with 2 mL works out as 10 units. Mix the same vial with 1 mL instead and that identical dose becomes 5 units. That's why the calculator needs all three numbers.
On a U-100 insulin syringe, units are a measure of volume: 100 units always equals 1 mL. The amount of semaglutide in those units depends on your vial's concentration. This table shows common syringe readings at three concentrations.
At 5 mg/mL, a single unit holds 0.05 mg. Misreading the syringe by even two or three lines changes the dose noticeably. The FDA has warned about people taking up to 20 times their intended dose of compounded semaglutide after confusing mg, mL, and units, including drawing 50 units instead of 5 (FDA alert).
Ozempic and Wegovy injections are FDA-approved and come as ready-to-use pens or prefilled syringes, Wegovy also comes as a tablet (Wegovy label), and Rybelsus is an oral tablet. Pens deliver set doses and don't use syringe units, so this calculator isn't for them.
This tool is for compounded semaglutide drawn from a vial. Compounded semaglutide isn't FDA-approved, and the FDA says salt forms like semaglutide sodium and semaglutide acetate are different active ingredients from the approved drug (FDA). Get semaglutide only through a licensed prescriber and pharmacy.
To learn the mixing process step by step, read our guide on how to reconstitute semaglutide. The general peptide calculator works for any other peptide you use, and PeptideKit can save your semaglutide protocol, remind you on injection day, and log every dose.
It depends on your concentration. At 2.5 mg/mL, 0.25 mg is 10 units on a U-100 syringe. At 5 mg/mL, it's 5 units. Enter your vial size and diluent volume above to get your exact number.
Divide 100 by the concentration in mg/mL. At 2.5 mg/mL, 1 mg is 40 units. At 5 mg/mL, 1 mg is 20 units.
10 units is 0.1 mL on a U-100 syringe. At 2.5 mg/mL that's 0.25 mg, and at 5 mg/mL it's 0.5 mg. The conversion table above covers other readings.
Work out the concentration (vial mg ÷ mL of diluent), divide your prescribed dose in mg by that concentration to get mL, then multiply by 100 to get units. The calculator does this automatically.
No. Branded pens use fixed doses or dose counters, not syringe units. This calculator is only for semaglutide drawn from a vial with an insulin syringe.
Always consult with qualified healthcare professionals before starting any peptide therapy protocol. This information is for educational purposes only and does not constitute medical advice.
Semaglutide Peptide Calculator
Enter your semaglutide vial size, how much diluent was added, and the dose your prescriber gave you in mg. The calculator shows how many units to draw on a U-100 insulin syringe.
Calculated Dosage
For a dose of 0.25 mg, pull the syringe to:
10.0 units
Concentration
2.50 mg/ml
Volume
0.100 ml
Syringe
30 units = 0.3ml
Syringe
Peptide Vial Quantity
5mg
Bacteriostatic Water
2ml
Desired Dose
0.25 mg
Use the dose on your prescription. Presets are shortcuts, not recommendations.
How It Works
1. Calculate concentration:
Peptide amount ÷ Water volume = 2.50 mg/ml
Peptide amount ÷ Water volume = 2.50 mg/ml
2. Find required volume:
Target dose ÷ Concentration = 0.100 ml
Target dose ÷ Concentration = 0.100 ml
3. Convert to syringe units:
(Required volume ÷ Syringe volume) × Syringe units = 10.0 units
(Required volume ÷ Syringe volume) × Syringe units = 10.0 units
How to Use the Semaglutide Calculator
This semaglutide peptide calculator converts the milligram dose on your prescription into units on a U-100 insulin syringe. Semaglutide doses are small, often a fraction of a milligram, so a few units either way makes a real difference. Let the calculator do the arithmetic, then double-check it against your pharmacy's instructions.
Step 1: Choose your syringe. A 0.3 mL (30 unit) syringe is usually easiest to read for small doses, since it's typically marked at every unit. Pick whichever size you actually have.
Step 2: Enter your vial size. Use the milligrams printed on your vial label. Tap Custom if your size isn't listed.
Step 3: Enter the diluent volume. This is how much bacteriostatic water (or other diluent) was added. If your pharmacy sent the vial pre-mixed, match the concentration on the label: a vial labelled 2.5 mg/mL is the same as 5 mg in 2 mL.
Step 4: Enter your prescribed dose in mg. Presets are shortcuts, not recommendations. Use the exact number your prescriber gave you.
With the defaults shown, 0.25 mg out of a 5 mg vial mixed with 2 mL works out as 10 units. Mix the same vial with 1 mL instead and that identical dose becomes 5 units. That's why the calculator needs all three numbers.
Semaglutide Units to mg Conversion Table
On a U-100 insulin syringe, units are a measure of volume: 100 units always equals 1 mL. The amount of semaglutide in those units depends on your vial's concentration. This table shows common syringe readings at three concentrations.
| Syringe units | Volume | At 1 mg/mL | At 2.5 mg/mL | At 5 mg/mL |
|---|---|---|---|---|
| 1 unit | 0.01 mL | 0.01 mg | 0.025 mg | 0.05 mg |
| 2 units | 0.02 mL | 0.02 mg | 0.05 mg | 0.1 mg |
| 5 units | 0.05 mL | 0.05 mg | 0.125 mg | 0.25 mg |
| 10 units | 0.1 mL | 0.1 mg | 0.25 mg | 0.5 mg |
| 20 units | 0.2 mL | 0.2 mg | 0.5 mg | 1 mg |
| 30 units | 0.3 mL | 0.3 mg | 0.75 mg | 1.5 mg |
| 50 units | 0.5 mL | 0.5 mg | 1.25 mg | 2.5 mg |
When You Don't Need This Calculator
Ozempic and Wegovy injections are FDA-approved and come as ready-to-use pens or prefilled syringes, Wegovy also comes as a tablet (Wegovy label), and Rybelsus is an oral tablet. Pens deliver set doses and don't use syringe units, so this calculator isn't for them.
This tool is for compounded semaglutide drawn from a vial. Compounded semaglutide isn't FDA-approved, and the FDA says salt forms like semaglutide sodium and semaglutide acetate are different active ingredients from the approved drug (FDA). Get semaglutide only through a licensed prescriber and pharmacy.
To learn the mixing process step by step, read our guide on how to reconstitute semaglutide. The general peptide calculator works for any other peptide you use, and PeptideKit can save your semaglutide protocol, remind you on injection day, and log every dose.
Frequently Asked Questions
How many units is 0.25 mg of semaglutide?
It depends on your concentration. At 2.5 mg/mL, 0.25 mg is 10 units on a U-100 syringe. At 5 mg/mL, it's 5 units. Enter your vial size and diluent volume above to get your exact number.
How many units is 1 mg of semaglutide?
Divide 100 by the concentration in mg/mL. At 2.5 mg/mL, 1 mg is 40 units. At 5 mg/mL, 1 mg is 20 units.
How much semaglutide is in 10 units?
10 units is 0.1 mL on a U-100 syringe. At 2.5 mg/mL that's 0.25 mg, and at 5 mg/mL it's 0.5 mg. The conversion table above covers other readings.
How do I calculate semaglutide dosage in units?
Work out the concentration (vial mg ÷ mL of diluent), divide your prescribed dose in mg by that concentration to get mL, then multiply by 100 to get units. The calculator does this automatically.
Can I use this for Ozempic or Wegovy pens?
No. Branded pens use fixed doses or dose counters, not syringe units. This calculator is only for semaglutide drawn from a vial with an insulin syringe.
Always consult with qualified healthcare professionals before starting any peptide therapy protocol. This information is for educational purposes only and does not constitute medical advice.