Prescription Refill Calculator
Calculate when to refill your prescription based on daily dosage and supply quantity. Avoid running out of medication.
Published by:
isCalculator Editorial Team
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How to use this tool?
This calculator helps you determine when you need to request a prescription refill based on your daily dosage and current supply.
- Enter your daily dosage (pills per day). Use decimals if needed (e.g., 0.5 for half a pill).
- Enter the supply quantity (total pills per refill, e.g., 30). Must be a whole number.
- Enter days until refill needed (how many days of medication you have left). Must be a whole number (0 if you’re out today).
- Click "Calculate Refill Date" to see the result.
What the result means: The calculator shows the total number of days from today until you need a refill. It adds your remaining days to the number of days your current supply will last (supply ÷ daily dosage), then rounds up to the nearest whole day.
Example: If you take 2 pills daily, have a 30-pill supply, and 10 days left, you’ll need a refill in 25 days (10 + 30÷2 = 10 + 15 = 25).
Previous Results
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Frequently Asked Questions
It calculates the number of days your current supply will last based on your daily dosage, then adds the days until you run out to give the total days until you need a refill.
Yes, as long as you know your daily dosage and the quantity per refill. It works for pills, liquids, or any unit you can measure.
Enter the total number of pills you take each day. The calculator will handle fractional doses if needed.
