Medication Refill Runway

Plan refill timing from medication-label instructions and your own inventory records.

Follow the prescription label and contact your pharmacist or clinician about any discrepancy, shortage, authorization question, missed/extra dose, or travel need. This calculator only organizes values you enter; it does not give medical advice or recommend rationing, skipping, splitting, doubling, or any other dosing change. It does not assess emergencies.

Privacy: Calculations stay in this page. Nothing is uploaded. Data is kept in memory unless you explicitly save it in this browser; downloads, printouts, and browser saves may expose sensitive health information on a shared device.

Medication and schedule

Label / medication nameLabel unit (tablet, mL, etc.)

Units on hand at start of inventory dateUnits per prescribed doseDoses per day

Optional daily schedule labels (comma-separated; count must equal an integer doses/day)

Inventory date (start of day)Quantity per refill (label units)Refills remaining

Lead times and buffer

Pharmacy lead daysClinician authorization lead daysPersonal buffer days

Travel and adjustments

Travel startTravel end

Pickup blackout dates (one YYYY-MM-DD per line)User-recorded adjustments (one line: YYYY-MM-DD | signed label units | note)

Adjustments are applied before that date's label-scheduled demand and must be on or after the inventory date. They record inventory changes only, never dosing instructions.

Portable data

Import JSON (maximum 1 MiB)

Runway plan

Enter label and inventory details to calculate.

Daily inventory ledger

Demand follows the entered label schedule; an uncovered amount is a calculation, not a dosing instruction.
Date	Starting units	Label-scheduled demand	Adjustment	Ending units	Note

Each row is a calendar date exactly as entered; no time-zone conversion is performed. The first uncovered day is the first date inventory cannot cover all label-scheduled doses. Negative ending inventory represents an arithmetic shortfall, not actual use.