When will I run out of pills?

Enter your total pill count, dose per administration, and how often you take them into the calculator above. It will show you the exact calendar date your pills will run out, plus a suggested refill date 5 days before so you never miss a dose.

Do I have enough medication for my trip?

Use the vacation planning feature in this calculator. Enter your travel dates and current pill count — it will tell you if you have enough medication to cover your trip, or exactly how many extra pills you need to request from your pharmacy or doctor before traveling.

How many days will this prescription last calculator?

This free calculator determines how many days your prescription will last based on your pill count, dose amount, and frequency. It also shows a weekly breakdown of pills used vs. remaining, the exact run-out date, and a suggested refill date. Works for any medication taken as tablets or capsules.

When should I request a prescription refill?

Most pharmacies recommend requesting a refill 5–7 days before you run out, to allow time for processing, insurance authorization, and any potential delays. This calculator shows a suggested refill date automatically. For mail-order pharmacies (90-day supply), request refills 10–14 days early to account for shipping time.

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How Long Will My Prescription Last?

Calculate exactly how many days your medication will last, when you'll run out, and when to request a refill. Includes a vacation planner to make sure you have enough pills for travel.

Prescription Details

Pills / Tablets Remaining Total pills in bottle (or remaining count)

Pills Per Dose How many pills you take each time

How Often

Start Date (default: today)

—

Enter your prescription details above.

🧳 Vacation Planning Helper

Check if you have enough medication for your trip.

Travel departure

Travel return

Disclaimer: This calculator provides estimates only. Actual usage may vary. Always follow your healthcare provider's dosing instructions and consult your pharmacist about refill timing.

When to use

Use this calculator to figure out when your medication will run out and when to request a refill. Helpful for planning ahead, especially before vacations, insurance changes, or switching pharmacies.

Common scenarios

New prescription: Enter the total pill count from a fresh bottle to see how many days it covers.
Mid-bottle check: Count remaining pills to find out exactly when you'll need a refill.
Travel planning: Use the vacation helper to ensure you have enough pills for your entire trip.
Insurance timing: Know when your supply ends to coordinate with insurance refill windows.

Refill timing tips

Retail pharmacy: Request refills 5–7 days before running out.
Mail-order (90-day): Request 10–14 days early for shipping time.
Controlled substances: Most states allow refills 2–3 days early; check local laws.
Prior authorization: If your medication requires PA, start the refill process even earlier (7–10 days for retail).

Quick Reference

Pill Count	Frequency	Days Supply
30 pills	Once daily	30 days
30 pills	Twice daily	15 days
60 pills	Twice daily	30 days
90 pills	Once daily	90 days
90 pills	Three times daily	30 days

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About This Tool

How the Prescription Duration Calculator Works

This calculator uses a simple but essential formula: Days Supply = Total Pills ÷ Pills Used Per Day. The pills used per day is determined by multiplying your dose amount (pills per dose) by your dosing frequency (times per day). From the days supply, we calculate the exact calendar date your medication will run out, and suggest a refill date 5 days before that.

Why Knowing Your Supply Duration Matters

Running out of medication — even for a day or two — can have serious health consequences depending on the drug. Medications for blood pressure, diabetes, thyroid conditions, seizures, and mental health often require continuous, uninterrupted use. Gaps in therapy can lead to:

Rebound effects: Blood pressure spikes, blood sugar fluctuations, seizure breakthrough
Withdrawal symptoms: Especially with antidepressants (SSRI discontinuation syndrome), benzodiazepines, and opioid medications
Disease progression: Missing doses of antibiotics, antivirals, or immunosuppressants can reduce treatment effectiveness
Hospitalization: In severe cases, missed doses lead to emergency department visits

Understanding Day Supply

"Day supply" is a pharmacy term that refers to the number of days a dispensed quantity of medication will last at the prescribed dosing regimen. Insurance companies use this to determine when you're eligible for a refill. Common day supplies are:

30-day supply: Standard retail pharmacy fill — most common for monthly prescriptions
60-day supply: Some insurers allow this for maintenance medications
90-day supply: Mail-order pharmacy standard — often cheaper per pill and more convenient

Tips for Managing Your Medication Supply

Set a phone reminder for your calculated refill date
Use automatic refills at your pharmacy when available
Keep a 3-day emergency buffer — ask your pharmacist about emergency supply dispensing laws in your state
Consider 90-day mail order for long-term medications — saves trips and often costs less
Before traveling: Request an early refill (most insurers allow "vacation overrides"), carry medication in original bottles, and bring a copy of your prescription

What to Do If You're Running Low

If you realize you'll run out before your next scheduled refill:

Call your pharmacy immediately — they may be able to provide a short emergency supply (most states allow 72 hours for non-controlled medications)
Contact your prescriber's office — they can call in an emergency refill or send a new prescription
Check for manufacturer coupons — programs like GoodRx or manufacturer patient assistance programs can help if cost is a barrier
Don't skip doses or cut pills without asking — some medications cannot be split safely, and abruptly stopping certain drugs is dangerous

💊 Practical Tips

Most insurance plans allow refills when you have 7–10 days of supply remaining (about 75% through your prescription).
For controlled substances (Schedule II–V), refill timing rules are stricter and vary by state — typically 2–3 days early maximum.
Mail-order pharmacies often provide 90-day supplies at the cost of two 30-day copays — ask your insurer about this option.
When traveling internationally, carry medications in the original pharmacy-labeled bottles and bring a letter from your doctor listing your medications.
If you take a half pill (0.5), ask your pharmacist if the tablet is scored — unscored tablets may not split evenly and could affect dosing accuracy.

Frequently Asked Questions

What if I miss a dose? A missed dose effectively extends your supply by one dose, but don't intentionally skip doses to make a prescription last longer. Follow your doctor's instructions for missed doses.

Can I get extra pills for travel? Yes — most insurance companies allow "vacation overrides" that let you fill early before extended travel. Call your insurance company and pharmacy at least 2 weeks before your trip.

Why does my pharmacy say I can't refill yet? Insurance companies calculate when your medication "should" run out based on the day supply submitted with the last fill. If you try to refill too early, the claim may be rejected. Most plans allow refills at about 75–80% through the supply.

Formula last verified: February 2026