When "Quantity ÷ Daily Dose" Isn't Enough
The standard days supply formula assumes the same dose every day. Plenty of real prescriptions don't work that way:
- Different doses on different days. For example 1 tablet Monday to Friday and 1½ on weekends, which is common with medications adjusted by blood tests.
- Weekly dosing. Some osteoporosis, vitamin and arthritis medications are taken once a week.
- Tapers. A dose that steps down over days or weeks, often used with steroids and some other medications.
For these, this calculator counts day by day from your start date instead of dividing.
Weekday Schedules
Enter what you take on each day of the week. The calculator shows your weekly total and average per day, then walks forward from the start date, subtracting each day's dose until there aren't enough tablets for the next one.
Example: 1 tablet Monday to Friday, 2 tablets Saturday and Sunday. That's 9 tablets a week, about 1.29 a day. A bottle of 60 lasts 47 days if you start on a Monday, and the exact run-out date depends on which weekday you start. That detail is lost when you just divide by the average.
For a once-weekly medication, enter the dose on your dosing day and 0 on the other six. Four tablets then covers 28 days.
Tapers
A taper lists steps: a daily amount and how many days to take it. Add the steps and the calculator gives the total tablets needed, the date of the last dose and the dates of each step.
| Step | Daily amount | Days | Tablets |
|---|---|---|---|
| 1 | 4 tablets | 3 | 12 |
| 2 | 3 tablets | 3 | 9 |
| 3 | 2 tablets | 3 | 6 |
| 4 | 1 tablet | 3 | 3 |
| Total | 30 tablets over 12 days | ||
Enter the number of tablets you received and the calculator checks it against the taper. If you'd come up short, it shows the date you'd run out so you can contact the pharmacy before then.
Follow the taper exactly as your prescriber wrote it. Stopping some medications suddenly, or stretching a taper to make tablets last, can be harmful. If the numbers don't add up, call your pharmacist.
Tips for Irregular Schedules
- A weekly pill organizer makes alternating doses much easier to follow and to count.
- If your dose changes often, recount your tablets after each change and recalculate.
- Ask the pharmacy how they recorded the days supply. For a complex schedule it may differ from your own count, and the recorded number is what your insurance uses.
For a single fixed daily dose, the standard days supply calculator is quicker, and the pill refill date calculator adds refill reminders and tracking.