Units to mg at three strengths
Take the strength from your vial’s label. The same units hold a different amount in each vial: 10 units are 1 mg at 10 mg per mL and 0.5 mg at 5 mg per mL.
| UnitsmL | At 2.5 mg/mL | At 5 mg/mL | At 10 mg/mL |
|---|---|---|---|
| 10.01 mL | 0.025 mg | 0.05 mg | 0.1 mg |
| 20.02 mL | 0.05 mg | 0.1 mg | 0.2 mg |
| 50.05 mL | 0.125 mg | 0.25 mg | 0.5 mg |
| 100.10 mL | 0.25 mg | 0.5 mg | 1 mg |
| 150.15 mL | 0.375 mg | 0.75 mg | 1.5 mg |
| 200.20 mL | 0.5 mg | 1 mg | 2 mg |
| 250.25 mL | 0.625 mg | 1.25 mg | 2.5 mg |
| 300.30 mL | 0.75 mg | 1.5 mg | 3 mg |
| 400.40 mL | 1 mg | 2 mg | 4 mg |
| 500.50 mL | 1.25 mg | 2.5 mg | 5 mg |
| 600.60 mL | 1.5 mg | 3 mg | 6 mg |
| 700.70 mL | 1.75 mg | 3.5 mg | 7 mg |
| 750.75 mL | 1.875 mg | 3.75 mg | 7.5 mg |
| 800.80 mL | 2 mg | 4 mg | 8 mg |
| 900.90 mL | 2.25 mg | 4.5 mg | 9 mg |
| 1001.00 mL | 2.5 mg | 5 mg | 10 mg |
Each unit is 0.01 mL, so at 10 mg per mL it holds 0.1 mg. The calculator above works out any strength, in either direction.
Units, mL and mg
A unit on an insulin syringe is a volume, not an amount of drug: 100 units are 1 mL on a U-100 syringe, so 1 unit is 0.01 mL. The mg in that volume depend on the strength, the mg in the vial divided by the mL they are in: 10 mg in 2 mL is 5 mg per mL.
Units to mg: units ÷ 100 = mL, and mL × the strength = mg. Mg to units: mg ÷ the strength = mL, and mL × 100 = units.
FDA has reported dosing errors with compounded semaglutide in vials where doses were given in units: patients mixed up mL, mg and units, and the units held a different dose at each strength.
The example in the calculator. A vial labelled 10 mg/mL: 20 units are 0.2 mL, and 0.2 mL × 10 mg/mL = 2 mg. The other way, 2 mg ÷ 10 mg/mL = 0.2 mL, which is 20 units.
For a vial you mixed
The strength is the mg in the vial divided by the water you added: a 10 mg vial with 2 mL of water is 5 mg per mL, so enter 10 and 2 above. The peptide calculator takes the vial, the water and the dose in one step.
Units are not IU
The lines of an insulin syringe are named after U-100 insulin, which holds 100 units in 1 mL. For any other drug they are only a volume, 0.01 mL each. A dose written in IU, as for HGH, needs the drug’s IU per mg: the HGH reconstitution calculator converts it.
Other calculators
- Insulin syringe units to mLUnits on a U-100 insulin syringe in mL, and mL in units.
- Semaglutide units to mgThe mg in the units you draw of a semaglutide vial, or the units for a dose, from the strength printed on the vial.
- Tirzepatide dosage calculatorUnits to draw for a tirzepatide dose, from the mg in the vial and the mL of liquid in it.
- Retatrutide dosage calculatorUnits to draw for a retatrutide dose, from the mg in the vial and the water you added.
Questions
How many mg is 10 units?
It depends on the strength. 10 units are 0.1 mL: 1 mg at 10 mg/mL, 0.5 mg at 5 mg/mL, 0.25 mg at 2.5 mg/mL. At another strength, multiply 0.1 mL by the mg per mL on your label.
How many units is 2.5 mg on an insulin syringe?
25 units at 10 mg/mL, 50 units at 5 mg/mL and 100 units, a full 1 mL syringe, at 2.5 mg/mL.
How many units is 1 mg?
10 units at 10 mg/mL, 20 units at 5 mg/mL and 40 units at 2.5 mg/mL.
Is a unit the same in every vial?
The volume is: 0.01 mL on a U-100 syringe. The mg in it are not, because they depend on the strength. Check the dose in mg with the strength on your label before you draw.
Sources
- BD Insulin Syringe, 510(k) K190054FDA, cleared 2019-10-21. U-100 syringes of 0.3, 0.5 and 1 mL and their lines.
- Dosing errors with compounded injectable semaglutideFDA alert of 2024-07-26. Doses given in units, mL, mg and units mixed up, strengths that vary by compounder.