“How many months is 180 tablets?” has a slippery word in it. A pharmacy month is usually 30 days, a lot of packs are 28, and a calendar month is anything from 28 to 31. This gives you the days first, then each kind of month, so you can pick the one your prescription is written in.
Tablets to months
Tablets ↔ months
Your tablets
Nothing you type here leaves your browser.
Common bottle sizes
| Tablets | 1 a day | 2 a day | 3 a day |
|---|---|---|---|
| 28 | 28 days | 14 days | 9 days |
| 56 | 56 days | 28 days | 18 days |
| 60 | 60 days | 30 days | 20 days |
| 84 | 84 days | 42 days | 28 days |
| 90 | 90 days | 45 days | 30 days |
| 120 | 120 days | 60 days | 40 days |
| 180 | 180 days | 90 days | 60 days |
Days are full days only: 28 tablets at 3 a day is 9 full days with one tablet over. Divide by 30 for pharmacy months: 180 tablets twice a day is 90 days, which is 3 months. The longer version, with why 28 and 30 both show up, is in how many months is 180 tablets.
Which month to use
Most US prescriptions count a month as 30 days, so a 90-day supply is three months. Packs made in weeks (28, 56, 84) count in 28-day fills, which is why a “monthly” 28-tablet pack runs out a couple of days before the calendar month does. Over a year that is 13 packs, not 12 — see 28-day vs 30-day prescriptions.
For a run-out date on the calendar instead of a count, use the refill date calculator; for pack rounding on a days-supply figure, the days supply calculator.
Common questions
180 tablets twice a day is how many months?
90 days, which is 3 months of 30 days. Counted as calendar months it is just under 3, about 2.96, because three calendar months average a little over 91 days.
How many months is 120 tablets at one a day?
120 days, which is 4 months of 30 days, or about 3.94 calendar months.
How many tablets do I need for 3 months at 2 a day?
180, counting a month as 30 days. Counting 28-day fills it is 168, and counting average calendar months it is 183.
Why does my monthly pack run out before the end of the month?
Many packs hold 28 tablets, which is four weeks. Every calendar month except a non-leap February is longer than 28 days, so a pack started on the 1st runs out 0 to 3 days before the month ends.
One thing this cannot do
This is an arithmetic tool, not medical advice. It works out numbers from what you type in — it does not know your medication, your prescription, or what you should do if something goes wrong. Anything about changing a dose, spacing doses differently, or handling a missed dose is a question for your doctor or pharmacist.