Refill date calculator

Enter what is actually in the bottle. The calculator works out the day your supply runs out, and the earlier day you should order by so you never get down to the last two pills on a weekend.

What to do with the number

The order-by date is the useful one. The run-out date tells you when you have a problem; the order-by date tells you when to act so you never have one.

Two things worth checking the moment you hit that date. First, whether the prescription has repeats left, or whether you need a new one — that is the step with a queue in front of it. Second, whether a review appointment is required, because appointments are booked weeks out and pills are not.

There is a longer write-up of the whole system in four ways to know you're running low, including the version that works with a pen and the bottle label. If you would rather not keep the count by hand, Doz tracks stock per medication and warns you at a pill threshold you set, rather than at a date that drifts.

Common questions

How many days of buffer should I leave?

Around seven days for a once-daily medication. That covers a weekend, a public holiday, and a pharmacy that has to order your medication in. If a refill needs a prescription renewal or a review appointment, leave considerably more — that step can take weeks.

Why calculate by pill count instead of by date?

A fixed refill date drifts the moment you skip a dose or take an extra one, and nothing tells you that it drifted. A pill count is tied to what is physically in the bottle, so it stays accurate.

Does having pills left mean I can get a refill?

No. Some prescriptions have a limited number of repeats before you need a new one, and some need a review appointment first. The pill count tells you about supply, not about access, so when you hit your threshold check how many steps are between you and the next box.

One thing this cannot do

This is an arithmetic tool, not medical advice. It works out dates and times from numbers 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.