This 30 day prescription refill calculator answers the two questions people have about monthly prescriptions: how many pills a 30-day supply is at your dose, and the exact date the next one is due. It also works as a 30 day refill date calculator for the whole year.
How Many Pills Make a 30-Day Supply?
30-Day Quantity = Pills per Day × 30
| Directions | Pills per day | 30-day quantity |
|---|---|---|
| ½ tablet daily | 0.5 | 15 |
| 1 tablet daily | 1 | 30 |
| 1½ tablets daily | 1.5 | 45 |
| 1 tablet twice daily | 2 | 60 |
| 1 tablet three times daily | 3 | 90 |
| 2 tablets twice daily | 4 | 120 |
If you received a different number, enter it under Pills dispensed and the calculator shows how far off a full 30 days you are.
When Is a 30-Day Refill Due?
Count your fill date as day 1. Day 30 is the last day covered, and day 31 is when the next fill is due. Filled on September 10? You're covered through October 9 and due October 10.
Because months aren't 30 days long, the due date moves:
- after a 31-day month it lands one day earlier in the month
- after February it lands two days later (one day in a leap year)
- over a full year, 30-day fills drift about five days earlier, so you need roughly 12.2 fills a year
The table in the results lists every 30-day refill date for the next 12 months and flags the ones that fall on a weekend.
Can I Refill a 30-Day Prescription Early?
Usually you can request it a few days before day 31, but there is no universal rule for how many. Plans set their own early-refill timing, and it often differs by medication. For a 30-day supply, a plan that waits until 80% has passed would allow the next fill around day 24; one that uses 90% would wait until day 27. Those are examples only. The refill too soon calculator compares the dates side by side, and your pharmacist can tell you the real one.
30-Day vs. 28-Day Fills
Some prescriptions are filled for 28 days instead of 30:
- Packaging. Many birth control pills and some blister packs come in 28-day cycles.
- Plan or state rules. Some controlled medications are limited to shorter fills.
- Predictability. 28 days keeps pickup on the same weekday every time.
A 28-day cycle means 13 fills a year instead of about 12. If your copay is per fill, that's worth knowing.
Moving to a 90-Day Supply
If you've been on the same dose of a long-term medication for a while, ask whether a 90-day supply is an option. It can mean fewer trips and, on many plans, a lower cost per day. See the 90-day refill calculator for quantities and mail-order timing, or go back to the main pill refill calculator to track several medications.