Free calculator
Reconstitution Calculator
Enter your vial amount, the water you add, and your dose to get the concentration, volume per dose, and units to draw.
This tool does arithmetic on numbers you enter. It does not recommend doses. Talk to your prescriber about your protocol.
- Concentration
- Volume per dose
- Units to draw
- Doses per vial
Results
How it works
- 1
Concentration = vial amount ÷ water added
- 2
Volume per dose = dose amount ÷ concentration
- 3
Units to draw = volume per dose × 100 for a U-100 syringe, or × 40 for a U-40 syringe
Worked example
A 5 mg vial with 2 ml of bacteriostatic water gives 2.5 mg/ml. A 0.25 mg dose is 0.1 ml, which is 10 units on a U-100 syringe.
Peptisy for iPhone
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Frequently asked questions
How do you calculate reconstitution?
Divide the vial amount by the water you add to get the concentration in mg per ml. Divide your dose by that concentration to get the volume to draw.
How much bacteriostatic water should I add?
This calculator does not recommend a water amount. Enter the amount specified for your vial and it computes the resulting concentration.
What is the difference between U-100 and U-40 syringes?
A U-100 syringe holds 100 units per ml. A U-40 syringe holds 40 units per ml. Use the type printed on your syringe barrel.
What does "units to draw" mean?
It is the volume of your dose, in ml, converted to the marking on your syringe barrel for the syringe type you selected.
Does this work for mcg doses?
Yes. Set the unit to mcg on the vial and dose fields and the calculator uses that unit consistently through the calculation.
Does Peptisy give medical advice?
No. Peptisy performs arithmetic on the numbers you enter. It does not recommend, adjust, or suggest a dose. Talk to your prescriber about your protocol.
This tool does arithmetic on numbers you enter. It does not recommend doses. Talk to your prescriber about your protocol.