1 mg to units on an insulin syringe
It depends on the concentration, and this page gives the number for every common one. 1 mg is 20 units at 5 mg/mL, 10 units at 10 mg/mL and 40 units at 2.5 mg/mL; 0.5 mg is 10, 5 and 20 units.
The short answer
There is no fixed number of units in 1 mg. A unit on an insulin syringe is a volume (0.01 mL on a U-100 syringe), and a milligram is a mass. How many units 1 mg takes depends on how concentrated the solution is, which you set when you add water. The table gives the answer for every common concentration.
How many units is 0.5 mL? mL to units
0.5 mL is 50 units on a U-100 insulin syringe, because 100 units is 1 mL and one unit is 0.01 mL. That holds for any liquid, since units measure volume. 0.1 mL is 10 units and 0.05 mL is 5 units. Going the other way, divide the units by 100: 11 units is 0.11 mL. On a U-40 syringe (usually veterinary) 0.5 mL is 20 units.
| Volume | U-100 units | U-40 units |
|---|---|---|
| 0.05 mL | 5 units | 2 units |
| 0.1 mL | 10 units | 4 units |
| 0.2 mL | 20 units | 8 units |
| 0.25 mL | 25 units | 10 units |
| 0.5 mL | 50 units | 20 units |
| 0.75 mL | 75 units | 30 units |
| 1 mL | 100 units | 40 units |
Volume to units needs no vial or water. The mg in each unit does, and that is the table below.
1 mg in units, by concentration
| Concentration | 1 mg = | U-100 units | 0.5 mg | 0.25 mg | 0.1 mg |
|---|---|---|---|---|---|
| 1 mg/mL | 1 mL | 100 units | 50 units | 25 units | 10 units |
| 2 mg/mL | 0.5 mL | 50 units | 25 units | 12.5 units | 5 units |
| 2.5 mg/mL | 0.4 mL | 40 units | 20 units | 10 units | 4 units |
| 3.33 mg/mL | 0.3 mL | 30 units | 15 units | 7.5 units | 3 units |
| 4 mg/mL | 0.25 mL | 25 units | 12.5 units | 6.2 units | 2.5 units |
| 5 mg/mL | 0.2 mL | 20 units | 10 units | 5 units | 2 units |
| 6.67 mg/mL | 0.15 mL | 15 units | 7.5 units | 3.7 units | 1.5 units |
| 10 mg/mL | 0.1 mL | 10 units | 5 units | 2.5 units | 1 units |
| 15 mg/mL | 0.067 mL | 6.7 units | 3.3 units | 1.7 units | 0.7 units |
| 20 mg/mL | 0.05 mL | 5 units | 2.5 units | 1.2 units | 0.5 units |
| 25 mg/mL | 0.04 mL | 4 units | 2 units | 1 units | 0.4 units |
| 40 mg/mL | 0.025 mL | 2.5 units | 1.2 units | 0.6 units | 0.2 units |
| 50 mg/mL | 0.02 mL | 2 units | 1 units | 0.5 units | 0.2 units |
1 mg in units, by vial and water
The same table, but starting from what you actually have in your hand: the mg on the vial and the mL of bacteriostatic water you added.
| Vial | Water | Concentration | 1 mg = |
|---|---|---|---|
| 2 mg vial | 1 mL | 2 mg/mL | 50 units |
| 2 mg vial | 2 mL | 1 mg/mL | 100 units |
| 5 mg vial | 1 mL | 5 mg/mL | 20 units |
| 5 mg vial | 2 mL | 2.5 mg/mL | 40 units |
| 5 mg vial | 3 mL | 1.67 mg/mL | 60 units |
| 10 mg vial | 1 mL | 10 mg/mL | 10 units |
| 10 mg vial | 2 mL | 5 mg/mL | 20 units |
| 10 mg vial | 3 mL | 3.33 mg/mL | 30 units |
| 15 mg vial | 2 mL | 7.5 mg/mL | 13.3 units |
| 15 mg vial | 3 mL | 5 mg/mL | 20 units |
| 20 mg vial | 2 mL | 10 mg/mL | 10 units |
| 20 mg vial | 3 mL | 6.67 mg/mL | 15 units |
| 30 mg vial | 2 mL | 15 mg/mL | 6.7 units |
| 30 mg vial | 3 mL | 10 mg/mL | 10 units |
| 50 mg vial | 5 mL | 10 mg/mL | 10 units |
| 60 mg vial | 3 mL | 20 mg/mL | 5 units |
Micrograms to units
For peptides dosed in mcg (BPC-157, ipamorelin, sermorelin and most repair and growth-hormone peptides) the same logic applies with a thousand-fold shift. 1 mg is 1,000 mcg.
| Setup | Concentration | 100 mcg | 200 mcg | 250 mcg | 500 mcg |
|---|---|---|---|---|---|
| 5 mg in 1 mL | 5000 mcg/mL | 2 | 4 | 5 | 10 |
| 5 mg in 2 mL | 2500 mcg/mL | 4 | 8 | 10 | 20 |
| 5 mg in 3 mL | 1667 mcg/mL | 6 | 12 | 15 | 30 |
| 10 mg in 2 mL | 5000 mcg/mL | 2 | 4 | 5 | 10 |
| 10 mg in 3 mL | 3333 mcg/mL | 3 | 6 | 7.5 | 15 |
| 10 mg in 5 mL | 2000 mcg/mL | 5 | 10 | 12.5 | 25 |
Why the number changes
Units mark volume. A U-100 insulin syringe holds 100 units in 1 mL, so one unit is 0.01 mL, whatever is in the liquid. When you dissolve 10 mg of peptide in 2 mL of water you get 5 mg per mL; 1 mg of that is 0.2 mL, or 20 units. Dissolve the same 10 mg in 1 mL and it is 10 mg per mL; 1 mg is now 0.1 mL, or 10 units. The dose has not changed. Only the mark on the barrel has.
The three-step version: concentration = vial mg / water mL. Volume = dose / concentration. Units = volume x 100. If your syringe is U-40 (usually veterinary) multiply by 40 instead, and read the syringe page first, because mixing those two up is a 2.5x error.
25 printable pages: dosing cards for the twelve most-used compounds at three water volumes, titration planners, a vial log, and five pages on what to do when it has already gone wrong.
Common questions
- How many units is 0.5 mL?
- 50 units on a U-100 insulin syringe, because 100 units is 1 mL. 0.1 mL is 10 units and 0.05 mL is 5 units. On a U-40 syringe 0.5 mL is 20 units.
- How many units is 1 mg on an insulin syringe?
- It depends on the concentration. At 5 mg/mL (for example a 10 mg vial in 2 mL) 1 mg is 0.2 mL, which is 20 units on a U-100 syringe. At 10 mg/mL it is 10 units. At 2.5 mg/mL it is 40 units.
- How many units is 0.5 mg?
- Half of whatever 1 mg is at your concentration: 10 units at 5 mg/mL, 5 units at 10 mg/mL and 20 units at 2.5 mg/mL on a U-100 syringe.
- How many units is 0.25 mg?
- A quarter of 1 mg, which is 250 mcg: 5 units at 5 mg/mL, 2.5 units at 10 mg/mL and 10 units at 2.5 mg/mL on a U-100 syringe.
- How many units is 0.1 mg?
- 0.1 mg is 100 mcg: 2 units at 5 mg/mL, 1 unit at 10 mg/mL and 4 units at 2.5 mg/mL on a U-100 syringe.
- How many units is 1 mL?
- On a U-100 insulin syringe, 100 units. On a U-40 syringe, 40 units. Units measure volume; check which scale is printed on your barrel.
- How many mcg is 10 units?
- Multiply the concentration in mcg/mL by 0.1. At 2,500 mcg/mL (5 mg in 2 mL), 10 units is 250 mcg.
Common conversions
The same three-step maths, pre-filled for the doses people ask about most. Units on a U-100 insulin syringe, where 100 units is 1 mL.
- mg to units calculator Any dose at any concentration, both directions, with the full reference tables
- Units to mg calculator What the units you drew are in milligrams
- 1 mg to units (this page)
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