Free calculator
Course end date calculator: when is my last dose?
For a course of tablets with a set number of days, such as antibiotics. Enter how often, for how many days and when you took the first dose – you get the date and time of the last dose and how many doses there are in total.
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Last dose
Wednesday, 4 November 2026around 11:00 pm
- Doses in total21
- Between doses8 h
- Day 7 of the courseWednesday, 4 November 2026
Your prescription sets how long the course lasts. Don't stop early or carry on longer without asking your doctor or pharmacist.
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 reminds you at every dose until the course's end date and records each one, so you can see what's been taken. Try it free
Guides on this topic
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ReadHow to work out when a course ends
Doses in total = doses per day × days. A 7-day course three times a day is 21 doses. If the first dose was at 7:00 and they are 8 hours apart, the 21st dose is on day 7 at 23:00.
The calendar day and the dose count only line up if you start with the first dose of the day. Starting in the evening is common – you pick up the prescription after work – and then the last dose falls on the morning after day 7. The calculator shows both so you can see the difference.
The prescription sets the length
How many days a course lasts is decided by the person who prescribed it. Don't stop early because you feel better and don't stretch the tablets to make them last longer – if something is unclear, ask your pharmacist. If you have tablets left over at the end, the pharmacy can take them back.
Finish the course on track
Reminders that stop on the last day
Add the course with an end date
Doserra stops the reminders after the last day.
Confirm each dose
Taken, Remind me later or Skipped – one tap from the notification.
Check what's been taken
Each dose is recorded, so you can see every one taken or missed.
Frequently asked questions
When does a 7-day course end?
On day 7, counting the day of the first dose as day 1. If you started in the evening, the last dose may fall on the morning of day 8 – the calculator shows the exact time.
Do I count doses or days?
Generally the number of doses matters. Your pharmacist can tell you which counts for your medicine.
What if I missed a dose during the course?
Check the package leaflet or ask your pharmacist – don't take a double dose to catch up unless you're told to.
Guides
Guides for everyday medicine routines
Practical advice on remembering doses, organising medicines and caring for someone else's.
A Weekly Medication Record Review in Five Checks
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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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