Convert milligrams into insulin-syringe units and millilitres — or read a syringe marking back into milligrams — at any concentration. This tool is drug-agnostic: it does the arithmetic for whatever is in the vial. For a specific medication, use the tirzepatide dosage calculator or the semaglutide dosage calculator.
Educational only. It converts a prescribed dose; it never chooses one. Always confirm against your pharmacy label.
This draw is more than 1 mL — it will not fit a standard 1 mL insulin syringe. Confirm the concentration and the syringe size with your pharmacy.
Units are a volume marking, not an amount of medication. The same units number is a different number of milligrams at every concentration, so read the mg/mL from the vial in your hand.
To convert milligrams to insulin-syringe units, divide the dose in milligrams by the concentration of the liquid in milligrams per millilitre. That gives you a volume in millilitres. Multiply that volume by 100 to read it on a U-100 insulin syringe, which prints 100 units per millilitre. A 2 mg dose drawn from a 10 mg/mL vial is 0.2 mL, or 20 units. To go the other way, divide the units by 100 to get millilitres, then multiply by the concentration to get milligrams. Milligrams and units can never be converted without the concentration, because units describe how much liquid is in the barrel and milligrams describe how much medication is dissolved in it.
dose mg ÷ concentration mg/mL × 100 = units U-100
Units on a U-100 insulin syringe. Every cell is (mg ÷ concentration) × 100, rounded to one decimal. Cells marked † exceed 100 units, which is more than a standard 1 mL syringe holds.
| Dose | 1 mg/mL | 2 mg/mL | 2.5 mg/mL | 5 mg/mL | 10 mg/mL | 20 mg/mL |
|---|---|---|---|---|---|---|
| 0.25 mg | 25 | 12.5 | 10 | 5 | 2.5 | 1.3 |
| 0.5 mg | 50 | 25 | 20 | 10 | 5 | 2.5 |
| 1 mg | 100 | 50 | 40 | 20 | 10 | 5 |
| 2 mg | 200 † | 100 | 80 | 40 | 20 | 10 |
| 2.5 mg | 250 † | 125 † | 100 | 50 | 25 | 12.5 |
| 5 mg | 500 † | 250 † | 200 † | 100 | 50 | 25 |
| 10 mg | 1000 † | 500 † | 400 † | 200 † | 100 | 50 |
† Exceeds a standard 1 mL U-100 syringe. Educational reference only — your prescriber sets your dose, and your pharmacy label is the source of truth for concentration. Important Safety Information →
On a U-100 syringe the volume is fixed by the marking; only the concentration changes what that volume contains.
| Units (U-100) | mL | 1 mg/mL | 2 mg/mL | 2.5 mg/mL | 5 mg/mL | 10 mg/mL | 20 mg/mL |
|---|---|---|---|---|---|---|---|
| 10 units | 0.1 mL | 0.1 mg | 0.2 mg | 0.25 mg | 0.5 mg | 1 mg | 2 mg |
| 25 units | 0.25 mL | 0.25 mg | 0.5 mg | 0.625 mg | 1.25 mg | 2.5 mg | 5 mg |
| 50 units | 0.5 mL | 0.5 mg | 1 mg | 1.25 mg | 2.5 mg | 5 mg | 10 mg |
| 100 units | 1 mL | 1 mg | 2 mg | 2.5 mg | 5 mg | 10 mg | 20 mg |
Insulin syringes are labelled by how many units they print per millilitre. A U-100 syringe divides one millilitre into 100 units, a U-50 into 50, and a U-40 into 40. The liquid volume is identical; only the printed scale differs. That means a 0.25 mL draw reads as 25 units on a U-100 barrel, 12.5 units on a U-50 barrel and 10 units on a U-40 barrel. If you convert a dose for one scale and then draw it on another, the amount of medication in the syringe will be wrong. Check which scale is printed on the barrel you are actually holding before you convert anything, and switch the syringe scale in the calculator above to match.
Divide the dose in milligrams by the concentration printed on the vial in mg/mL. That gives you millilitres. Multiply millilitres by 100 to get units on a U-100 insulin syringe. For example, 2 mg from a 10 mg/mL vial is 0.2 mL, which is 20 units. Milligrams alone can never be converted to units — you always need the concentration.
It depends on the concentration of the liquid in the syringe. On a U-100 syringe, 25 units is always 0.25 mL. At 1 mg/mL that is 0.25 mg; at 5 mg/mL it is 1.25 mg; at 10 mg/mL it is 2.5 mg; at 20 mg/mL it is 5 mg. Units measure volume, not the amount of medication.
No, and treating them as interchangeable is the most common conversion error. Units are a volume marking on the barrel of a syringe. Milligrams are a mass of medication. The concentration in mg/mL is what connects the two, and it differs between vials, pharmacies and products.
The number is how many units the syringe prints per millilitre. A U-100 syringe marks 100 units per mL, a U-50 marks 50 units per mL, and a U-40 marks 40 units per mL. The same 0.25 mL draw reads as 25 units on a U-100, 12.5 units on a U-50 and 10 units on a U-40, so the syringe type has to match what you are reading.
No. It converts a dose that has already been prescribed into a syringe marking and back again. It does not suggest, adjust or titrate a dose. Your prescriber sets the dose, and the label on your own vial is the source of truth for concentration.
Converting a specific medication? Use the tirzepatide dosage calculator or the semaglutide dosage calculator. Comparing what a prescription costs? See what tirzepatide costs in 2026 and the cheapest GLP-1 cost comparison.
Related tools & guides: all GLP-1 calculators · tirzepatide dosing chart
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