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This free mg-to-units converter turns a peptide dose in milligrams into the matching units on a U-100 insulin syringe — and back. Enter your reconstituted concentration (mg/mL), your dose (mg) and the syringe scale to get the exact units to draw. Arithmetic only — not medical advice.
Units = (dose ÷ concentration) × scale. On a U-100 syringe, 100 units = 1 mL. Arithmetic only — not medical advice.
How many units is 1 mg?
1 mg is 10 units at 10 mg/mL, 20 units at 5 mg/mL and 40 units at 2.5 mg/mL on a U-100 syringe. The answer changes with concentration because syringe units measure volume, not dose.
| Concentration | Volume | U-100 units |
|---|---|---|
| 1 mg/mL | 1 mL | 100 |
| 2 mg/mL | 0.5 mL | 50 |
| 2.5 mg/mL | 0.4 mL | 40 |
| 5 mg/mL | 0.2 mL | 20 |
| 10 mg/mL | 0.1 mL | 10 |
How many units is 2 mg?
2 mg is 20 units at 10 mg/mL, 40 units at 5 mg/mL and 80 units at 2.5 mg/mL on a U-100 syringe. At 1 mg/mL it is 200 units, which is more than one 1 mL syringe holds.
| Concentration | Volume | U-100 units |
|---|---|---|
| 1 mg/mL | 2 mL | 200 |
| 2 mg/mL | 1 mL | 100 |
| 2.5 mg/mL | 0.8 mL | 80 |
| 5 mg/mL | 0.4 mL | 40 |
| 10 mg/mL | 0.2 mL | 20 |
| Vial | 1 mL water | 2 mL water | 3 mL water | 5 mL water |
|---|---|---|---|---|
| 2 mg | 2 | 1 | 0.67 | 0.4 |
| 5 mg | 5 | 2.5 | 1.67 | 1 |
| 10 mg | 10 | 5 | 3.33 | 2 |
| 15 mg | 15 | 7.5 | 5 | 3 |
| 20 mg | 20 | 10 | 6.67 | 4 |
| 30 mg | 30 | 15 | 10 | 6 |
Concentration = vial strength ÷ bacteriostatic water added. A 10 mg vial with 2 mL of water gives 5 mg/mL.
| Dose | 1 mg/mL | 2 mg/mL | 2.5 mg/mL | 5 mg/mL | 10 mg/mL |
|---|---|---|---|---|---|
| 0.1 mg (100 mcg) | 10 | 5 | 4 | 2 | 1 |
| 0.25 mg (250 mcg) | 25 | 12.5 | 10 | 5 | 2.5 |
| 0.5 mg (500 mcg) | 50 | 25 | 20 | 10 | 5 |
| 1 mg (1,000 mcg) | 100 | 50 | 40 | 20 | 10 |
| 2 mg (2,000 mcg) | 200 | 100 | 80 | 40 | 20 |
| 2.5 mg (2,500 mcg) | 250 | 125 | 100 | 50 | 25 |
| 5 mg (5,000 mcg) | 500 | 250 | 200 | 100 | 50 |
On a U-100 syringe, 100 units = 1 mL, so units = (dose ÷ concentration) × 100. Values are syringe units, not mg. Amber values exceed 100 units — more than one standard 1 mL U-100 syringe holds, so that combination needs a more concentrated solution. IU is not shown on purpose: an international unit is defined per-substance by biological activity, so there is no universal mg-to-IU factor — see mcg vs mg vs IU.
The same formula works for solutions supplied at higher concentrations.
| Dose | 100 mg/mL | 200 mg/mL | 250 mg/mL |
|---|---|---|---|
| 50 mg | 50 | 25 | 20 |
| 100 mg | 100 | 50 | 40 |
| 200 mg | 200 | 100 | 80 |
| 250 mg | 250 | 125 | 100 |
| 300 mg | 300 | 150 | 120 |
| 500 mg | 500 | 250 | 200 |
| 600 mg | 600 | 300 | 240 |
Values are U-100 syringe units, not mg. Amber values exceed 100 units, more than one standard 1 mL U-100 syringe holds.
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Bacteriostatic water calculator →
Full calculator →
Peptide library →
Half-life calculator →
More mg to units conversions
100 mcg to units
200 mcg to units
250 mcg to units
500 mcg to units
1.5 mg to units
2.4 mg to units
2.5 mg to units
5 mg to units
10 mg to units
15 mg to units
Frequently asked questions
What does “units” mean on an insulin syringe?
On a U-100 insulin syringe, 100 units equal 1 milliliter, so the unit marks are really just fine volume markings. The converter turns a dose in milligrams into the matching unit mark to fill the syringe to — it is not measuring a dose of insulin.
How do I convert milligrams to syringe units?
Divide your dose in milligrams by the solution’s concentration in mg/mL to get the volume in milliliters, then multiply by 100 for a U-100 syringe. The converter does this in both directions — enter a dose to get units, or units to get the delivered dose.
What if my syringe isn’t U-100?
The converter assumes a U-100 scale (100 units per milliliter), which is the most common insulin syringe. If your syringe uses a different scale, the unit marks will not match — check the scale printed on the barrel and enter the matching value.
Where does the concentration come from?
You provide it. The concentration in mg/mL depends on how the vial was reconstituted — use the bacteriostatic water calculator or the full peptide calculator to work it out, then enter it here.
Is this calculator medical advice?
No — it is arithmetic and reference only. It does not recommend a dose and does not assess whether any dose is appropriate. Verify with a clinician, the product label, or a pharmacist.