Prescription Run-Out Date Calculator
Last reviewed: June 2026
Estimate when a prescription supply may run out from the fill date and days supplied. This is basic date math for planning only, not medical, dosing, insurance, or dispensing advice.
Enter supply details
Estimated run-out date
Jul 28, 2026
29 day(s) from today based on the values entered.
This calculator estimates a run-out date using basic days-supply math. It does not tell you whether to take more or less medication or whether a refill can be processed.
Run-out date formula
Estimated run-out date = fill date + days supplied. If the fill date counts as Day 1, the calendar offset is days supplied minus one. For example, a 30-day supply filled on June 1 runs through about June 30 when the fill date counts as Day 1.