Vial to Units

Vial supply calculator

Enter the vial amount, your prescribed dose and how many injections per week your prescription calls for. Get doses per vial, how long one vial lasts and how many vials a number of weeks needs.

/ week
weeks

Enter the vial amount and your prescribed dose.

Arithmetic only. This tool does not recommend a dose or a schedule; use the ones your prescriber gave you.

The formula

doses per vial = amount in vial ÷ dose (rounded down to whole doses) weeks per vial = doses per vial ÷ injections per week days per vial = weeks per vial × 7 vials needed = (weeks × injections per week) ÷ doses per vial (rounded up)

Only full doses are counted. Whatever is left after the last full dose is shown separately and is not carried over to the next vial.

The result is a count, not a shelf life. A mixed vial has a discard date, and a vial can reach that date before it is empty. Use the storage instructions and discard date from your pharmacy label.

Questions

How many doses are in a vial?

Divide the amount in the vial by the amount in one dose, using the same unit for both. A vial that holds 20 times your dose holds 20 doses. The water you add does not change this number.

Does adding more water give me more doses?

No. Water changes the volume of each draw, not the amount in the vial. The number of doses depends only on the vial amount and the dose.

Why might I get fewer doses than the calculator shows?

A small amount of liquid stays in the needle and syringe tip after each injection, and some stays in the vial. The calculator does not subtract these losses, so treat the result as an upper limit.

Does the calculator tell me how often to inject?

No. You enter the frequency from your prescription. The calculator only multiplies and divides the numbers you give it.

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