Units to mL Calculator (Insulin Syringe)
Convert insulin-syringe units to volume in mL on a U-100, U-50, or U-40 syringe. Add your concentration to also see the dose in mg.
Updated June 2026
Use mcg/mL for most peptides, mg/mL for compounded GLP-1.
Draw syringe to
0 units
(0.00 mL)
units → mL on U-100
| Units | Volume (mL) | Dose (mg) |
|---|---|---|
| 5 units | 0.05 | — |
| 10 units | 0.10 | — |
| 20 units | 0.20 | — |
| 25 units | 0.25 | — |
| 50 units | 0.50 | — |
| 75 units | 0.75 | — |
| 100 units | 1.00 | — |
Enter a working concentration to see the dose in mg.
For educational and research purposes only. This calculator provides estimates based on standard formulas.
Always verify calculations with your healthcare provider before use. We assume no liability for dosing errors, adverse events, or outcomes resulting from use of this tool.
Units to mL reference (U-100 / U-50 / U-40)
Units to mL only depends on the syringe. The mg column needs your concentration.
| Units | U-100 (mL) | U-50 (mL) | U-40 (mL) |
|---|---|---|---|
| 10 units | 0.10 | 0.20 | 0.25 |
| 20 units | 0.20 | 0.40 | 0.50 |
| 25 units | 0.25 | 0.50 | 0.625 |
| 50 units | 0.50 | 1.00 | 1.25 |
| 75 units | 0.75 | 1.50 | 1.875 |
| 100 units | 1.00 | 2.00 | 2.50 |
Why units to mL only depends on the syringe
Units are marks on the barrel that measure volume, not drug. A U-100 syringe is calibrated so that 100 units fills exactly 1 mL. A U-50 puts 50 units in 1 mL. A U-40 puts 40 units in 1 mL. So to turn units into mL you only need to know which scale is printed on your syringe — the drug concentration doesn't enter the picture.
When concentration matters
Concentration only matters when you want to know how much drug is in that volume. 50 units on a U-100 is always 0.5 mL. At 2.5 mg/mL that 0.5 mL is 1.25 mg. At 5 mg/mL the same 50 units is 2.5 mg. Enter your concentration in the calculator above and the mg column fills in.
A quick worked example
You drew 50 units on a U-100 syringe. That's 50 ÷ 100 = 0.50 mL of liquid, no matter what's in the vial. If you reconstituted a 5 mg vial with 2 mL of BAC water (2.5 mg/mL), 0.50 mL is 1.25 mg. If you used 1 mL of BAC water instead (5 mg/mL), the same 50 units is 2.5 mg. Same draw, double the dose.
Working from a dose instead? Use the mg to units calculator to go the other direction.
Frequently Asked Questions
How many mL is 50 units on an insulin syringe?
On a U-100 syringe, 50 units is 0.50 mL (half the barrel). On a U-50 it's 1.00 mL (the full barrel). On a U-40 it's 1.25 mL. The conversion is units ÷ syringe factor.
How many mL is 100 units?
On a U-100 syringe, 100 units is 1.00 mL — the full barrel. On a U-50 it's 2.00 mL and on a U-40 it's 2.50 mL.
How do you convert units to mL?
Divide units by the syringe factor: 100 for U-100, 50 for U-50, 40 for U-40. 30 units on a U-100 is 30 ÷ 100 = 0.30 mL.
Do I need a concentration to convert units to mL?
No. Units to mL is pure syringe scale — it only depends on which syringe you're holding. You only need a concentration if you also want to know how many mg or mcg those units represent.
How many mg is 50 units?
It depends on your concentration. At 2.5 mg/mL on a U-100 syringe, 50 units is 0.5 mL, which is 1.25 mg. Enter your concentration above to see your exact mg.
What's the difference between a U-100 and a U-40 syringe?
The printed scale. A U-100 marks 100 units per mL; a U-40 marks 40 units per mL. The same volume reads as different unit counts — always read off the syringe you're holding.
See also: units vs mL vs mg explainer and how to read an insulin syringe.
How to use this calculator
Pick your syringe
U-100 is the standard 1 mL insulin syringe. U-50 and U-40 use a different scale.
Enter the units
Type the number of units you're drawing. The calculator returns the volume in mL immediately.
Add concentration (optional)
Enter your working concentration to also see how many mg or mcg those units contain.
Save the math with every dose
Regimen keeps your concentration on file and pre-fills the draw amount on every injection log.
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