Free calculator
How many tablets do I need for 30 days? Tablet calculator
Choose how often you take the medicine and for how many days. You get the number of tablets you need and the date of the last dose – handy for a 30- or 90-day supply, a course of treatment or a trip.
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You need
90tablets
- Doses in total90
- Last dose onThursday, 26 November 2026
Tablets = tablets per dose × doses per day × days. The start day counts as day 1. Your prescription or the package leaflet sets how long to take it.
This calculator does arithmetic on the numbers you enter. It doesn't replace the instructions on your prescription label or the advice of your pharmacist or doctor.
Doserra keeps this count for you: every dose you confirm comes off the stock, and you're reminded to refill before you run out. Try it free
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ReadHow many tablets for 30 days?
Tablets = tablets per dose × doses per day × days. One tablet a day for 30 days is 30 tablets; twice a day, 60; three times a day, 90. For a 90-day supply, multiply by 90 instead: three tablets a day for 90 days is 270 tablets.
"Every 8 hours" means 3 doses a day, "every 12 hours" 2 and "every 6 hours" 4, so the same formula works for interval schedules. Half a tablet per dose? Enter 0.5.
28 days or 30 days?
Many packs hold 28 tablets – four weeks – rather than 30. If your pack has 28 and you take one a day, it covers 28 days, so a monthly refill comes a little earlier each month. Use the "How long will they last?" switch to see exactly when a pack runs out.
Your prescription comes first
The calculator only multiplies the numbers you enter. How much to take and for how long is set by your prescription or the package leaflet; ask your pharmacist if anything is unclear, and don't stop or stretch a course on your own.
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Let Doserra track what's left
Enter your stock once
How many tablets you have right now.
Confirm each dose
Every dose you mark as Taken comes off the count.
Get the refill reminder
Doserra warns you before you run out – a free feature.
Frequently asked questions
How many tablets for 30 days at 3 a day?
90 tablets: 3 doses a day × 30 days, with one tablet per dose. For 90 days it's 270.
How many tablets is a 90-day supply?
Multiply the tablets you take per day by 90. One a day is 90 tablets, two a day 180, three a day 270.
How many months is 180 tablets?
At one tablet a day, about six months; at two a day, about three months (90 days). Switch to "How long will they last?" to get the exact date.
Does the calculator tell me my dose?
No. It only multiplies what you enter from your prescription or leaflet. Questions about your dose belong with your pharmacist or doctor.
Guides
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ReadNever wonder again whether you took your medicine.
Add a medicine in a minute and Doserra reminds you at every dose, keeps the history and warns you before it runs out. Free for 2 medications, no account.
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