Prescription Refill Calculator

Are you wondering when your next refill date is? Manually counting the days on a calendar can be quite boring and maybe daunting. That’s why we’ve designed this online prescription refill calculator to help you automatically determine the next day you should be going for your refill.

Try it out!

About Our Prescription Refill Calculator

This prescription refill calculator is designed to help you determine the date you should be going for your next medication refill.

Prescribed medications often have a duration for which it is to be used. This duration is often decided by the doctor or prescriber. 

Depending on the condition being treated and the response of the patient to the drug treatment, there may be a need to continue taking the meds for an extended period.

In some cases, doctors don’t often prescribe medications for an overly long period. Rather, they prescribe for a sufficient period and then ask the patient to come back again.

Prescribing in small amounts allows the patient to come back again for review from which the doctor can decide whether to continue treatment with the original drug, change to a new drug, or discontinue treatment altogether.

It also helps to lift some financial burden off the patient as it is easier to buy a drug for a month than a year for most people. It also ensures that the patient adheres to the medication while additionally preventing drug wastage.

How to calculate your prescription refill date?

You can calculate your prescription refill date by simply writing down the date your medications were dispensed to you (fill date) and then adding the total number of days the dispensed drug is meant to last (days supply) to it. 

The resulting date obtained is your refill date which is also the date your medications will finish if taken as advised.

Here are the steps involved in calculating a prescription refill date.

• Step 1: Identify the date the prescription was filled.
• Step 2: Calculate the days supply by multiplying the number of units or pills you take per day by the number of days the prescription is intended to last. You can do this easily by using our days supply calculator.
• Step 3: Determine the Refill Date by adding the total days of supply to the date the prescription was filled. This will give you the date when your current prescription will run out which is also the date you should be going for a refill so as not to miss the next dose.

Example Calculation

Let’s say you have a prescription for a 30-day supply of medication (tablets), and you filled the prescription on January 1st.

First of all, calculate the Days Supply using the formula below or our online calculator:

Days of supply = Tablets taken per day × Days intended to last

Assuming you take 2 tablets per day:

Days supply = 2 tablets per day × 30 days intended to last 

= 60 days of supply

Now, proceed to calculate the refill date as shown below:

Refill date = Date filled + Total days of supply

= January 1st + 60days

= March 1st

In this example, your prescription refill date would be March 1st.

How to Calculate a 28-day Prescription Refill?

• Write down the exact date you take the first dose from the new 28-day medication supply for your records.
• Flip your calendar forward 27 days from the first dose date. Highlight or circle the date that lands on the 27th day – this marks the date you need to take the final dose from your current 28-day supply.
• To pinpoint when your next 28-day refill period can start, add 1 day to your last scheduled dose date. For example, if your last dose from the initial supply is August 2nd, then August 3rd becomes day 1 of your next 28-day refill period.
• Remember that each dispensed 28-day prescription supply should provide 28 days of medication. The last dose date indicates the end of the 28-day cycle, with the very next day starting the clock for the following 28-day window when your next refill can be filled.

How to Calculate a 30-day Prescription Refill?

• On the date that you take the first dose of your new prescription medication, write down that exact date for your records
• Count forward 29 days on your calendar from the date of your first dose. Circle or highlight the date that lands on 29 days later – this is the date you must take the final dose from your current 30-day supply.
• Calculate when your next 30-day refill period can begin by adding 1 day to the last dose date. So if your last scheduled dose from the initial supply is, for example, July 5th, then July 6th marks day 1 of your next 30-day refill period.
• Note that each dispensed prescription supply is expected to last 30 days. The final dose date signals the end of the 30-day cycle and the very next day starts the clock for the following 30-day window for your next permissible refill.

How to Calculate a 90-day Prescription Refill?

• On the date that you take the first dose of your new prescription medication that is filled as a 90-day supply, document that exact date for your records.
• Count forward 89 days on your calendar from the date of your first dose. Highlight or circle the date that lands on the 89th day – this is the date you must take the final dose from your current 90-day supply.
• To calculate when your next 90-day refill period can start, add 1 day to the date of your last dose. So if your scheduled last dose from the initial 90-day supply is, for example, September 12th, then September 13th marks day 1 of your next eligible 90-day refill period.
• Be aware that each dispensed prescription supply is expected to provide a 90-day supply. The final dose date signals the end of the 90-day cycle, and the very next day starts the clock for the following 90-day window when you can receive your next 90-day refill.

What Does 2 Refills Mean?

When a prescription states it allows for “2 refills”, it means you are able to fill that prescription a total of 3 times.

Here is what the 2 refills indicate:

• Original prescription fill – This is the first time you fill the prescription at the pharmacy to receive your initial supply of medication.
• 1st refill – Once you have finished taking the originally dispensed medication, you can then fill the prescription a second time. This would use up one of the authorized refills.
• 2nd refill – After finishing the supply from the first refill, you would still have one authorized refill remaining that allows you to fill the prescription for a 3rd and final time.

So in total, “2 refills” means you can fill the prescription for your initial need plus two more times – making 3 total prescription fills allowed for that prescribing order. 

The refills can generally be filled over the course of one year, provided refills are still available for that prescription order.