Free & Easy to Use

処方箋 リフィル計算機

Calculate your exact prescription refill date in seconds. Stay on top of your health with our intelligent, easy-to-use refill date calculator.

Calculate Your Refill Date

Enter your prescription details below and get your exact refill date instantly.

How to Use the Medication Refill Calculator

To use the medication refill calculator, enter 4 pieces of information: the medication name, total quantity dispensed, number of pills taken per day, and the date the prescription was filled. The refill date calculator computes your exact prescription refill date based on these inputs.

1

Enter Your Medication Name

Type the name and dosage of the prescribed medication, such as "Lisinopril 10mg" or "Metformin 500mg." The medication name helps you track multiple prescriptions at a time.

2

Input Total Quantity and Daily Dosage

Enter the total number of tablets or capsules dispensed by your pharmacy (for example, 30 or 90). Then, enter how many pills you take each day. The prescription refill calculator accepts fractional values like 0.5 for half a tablet.

3

Set the Fill Date

Select the date your pharmacy dispensed the prescription. The refill date calculator defaults to today's date, but you can change the fill date to match your prescription label.

4

View Your Results

Click "Calculate Refill Date" to see your exact refill date, days remaining, supply percentage, a visual timeline, and a recommended refill-by date that accounts for pharmacy processing delays.

Frequently Asked Questions

Answers to common questions about prescription refill calculations and this tool.

To perform 30 day prescription refill calculations, divide the total quantity dispensed by the daily dose and verify the result equals 30 days. For a 30 day supply of a once-daily medication, the pharmacy dispenses 30 tablets. For a twice-daily medication, the pharmacy dispenses 60 tablets (60 ÷ 2 = 30 days). Most insurance plans allow a refill when 75% of the 30 day supply has been used—around day 22 to 25. Enter your quantities in the calculator above to get the exact date for a 30 day prescription.

To perform 90 day prescription refill calculations, divide the total quantity dispensed by the daily dose and confirm the result equals 90 days. A 90 day supply of a once-daily medication requires 90 tablets. A twice-daily medication requires 180 tablets (180 ÷ 2 = 90 days). Mail-order pharmacies commonly dispense 90 day supplies to reduce cost per unit and pharmacy visits. Insurance plans typically allow a 90 day refill around day 80 to 83. Use the calculator with 90 tablets and 1 per day to see the exact 90 day prescription refill date.

To perform 28 day prescription refill calculations, divide the total quantity dispensed by the daily dose and confirm the result equals 28 days. Controlled substance prescriptions (Schedule II medications like Adderall and Oxycodone) use 28 day cycles instead of 30 day cycles. A once-daily controlled substance prescription dispenses 28 tablets with a refill eligibility date 28 days from the fill date. This tool computes 28 day supply schedules—enter 28 for total pills and 1 per day to see your controlled substance refill date.

A refill calculator is a digital health tool that estimates when a medication supply will run out based on quantity dispensed and daily dosage. This tool takes 3 core inputs—total pills, pills per day, and fill date—and returns the exact date the supply reaches zero. Patients use refill calculators for medication adherence, pharmacy planning, and avoiding gaps in treatment. Healthcare providers and pharmacies use day supply calculations for insurance billing, inventory management, and refill authorization.

NNMC Refill Policy

The National Naval Medical Center (NNMC) refill policy requires patients to request prescription refills 7 to 10 business days before the current supply runs out. NNMC pharmacy accepts refill requests through 3 channels: the automated phone refill line, in-person at the pharmacy window, and the TRICARE online patient portal. This calculator helps NNMC patients determine their next refill date and plan requests within the 7 to 10 day advance window required by NNMC refill policy.

No, all calculations run in your web browser. This tool does not collect, store, or transmit medication information to any server. No account registration is required, and no cookies track your prescription data.

Yes, enter the total number of pills taken per day in the "Pills Per Day" field. Take 1 tablet in the morning and 1 tablet at night—enter "2" as the daily dose. The medication refill calculator accepts fractional doses like 0.5 for half-tablet dosages.

The recommended refill-by date is set 3 to 5 days before the supply runs out. This buffer accounts for 3 common delays: pharmacy processing time (1 to 2 business days), insurance prior authorization reviews (1 to 3 business days), and weekends or holidays when pharmacies may be closed. Refilling 3 to 5 days early avoids gaps in medication adherence.

Yes, this tool is 100% free with no registration, no subscription, and no limits. Use it for any number of medications, as many times as needed. The calculator works on all devices—desktop, tablet, and mobile browsers.

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