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Peptide reconstitution calculator
Enter the amount of powder in the vial, the water you added and your dose. The calculator shows how many units to draw on an insulin syringe, and every step of the math, so you can check it.
- Syringes
- U-100 · U-40
- Math shown
- Every step
- Sent anywhere
- Nothing
- 5 mg ÷ 2 ml = 2.5 mg per ml
- 250 mcg ÷ 2.5 mg/ml = 0.1 ml
- 0.1 ml × 100 = 10 units
How syringe units are calculated
Three lines of arithmetic. The calculator above shows them with your own numbers.
-
01
Concentration
Divide the amount in the vial by the water you added. That’s how much of the compound is in each milliliter.
Example5 mg ÷ 2 ml = 2.5 mg/ml -
02
Volume of one dose
Divide your dose by the concentration. Convert to the same unit first: 1 mg = 1,000 mcg.
Example250 mcg ÷ 2,500 mcg/ml = 0.1 ml -
03
Syringe units
Multiply the volume by the syringe’s units per milliliter: 100 for a U-100 insulin syringe, 40 for U-40.
Example0.1 ml × 100 = 10 units
The same formula, different vials
Examples of the arithmetic only, not dosing guidance. Use the numbers your clinician gave you.
| Vial | Water | Concentration | Dose | Volume | Draw to |
|---|---|---|---|---|---|
| 5 mg | 2 ml | 2.5 mg/ml | 250 mcg | 0.1 ml | 10 units |
| 10 mg | 2 ml | 5 mg/ml | 500 mcg | 0.1 ml | 10 units |
| 10 mg | 3 ml | 3.33 mg/ml | 250 mcg | 0.075 ml | 7.5 units |
| 2 mg | 1 ml | 2 mg/ml | 100 mcg | 0.05 ml | 5 units |
| 5 mg | 2.5 ml | 2 mg/ml | 1 mg | 0.5 ml | 50 units |
Reading the result
-
01
What is a “unit” on an insulin syringe?
A marking on the barrel, not an amount of the compound. On a U-100 syringe, 100 units equal 1 ml, so 10 units are 0.1 ml. How much of the compound that holds depends on how you mixed the vial, which is what the calculator works out.
U-1001 unit = 0.01 ml -
02
U-100 or U-40?
Check the label on the syringe package. Most insulin syringes sold in the US are U-100, in 0.3, 0.5 and 1 ml sizes. A U-40 syringe has 40 units per ml, so the same volume reads as fewer units.
U-401 unit = 0.025 ml -
03
Why does my result fall between markings?
A 1 ml U-100 syringe is marked every 2 units, smaller syringes every unit. A result like 7.5 units can’t be read exactly. The calculator warns you; in the Vialmate app the “Water to add” mode shows how much water makes your dose land on a whole number of units.
Markings1 ml: every 2 units
0.3 / 0.5 ml: every unit -
04
Where do I read the dose on the syringe?
At the edge of the rubber stopper that faces the needle. The drawing above is laid out the same way: needle on the left, zero at the needle.
Read atThe stopper’s needle-side edge
Mix once, then never redo the math.
In Vialmate you save the vial you mixed, and every dose on your schedule shows the units for your syringe. Reminders at each dose, a log of every injection, and a heads-up before the vial runs out. See how it works
This calculator only does arithmetic on the numbers you enter. It does not recommend a dose and is not medical advice. Always follow your clinician’s instructions, and double-check the result before you draw.