Prescription Refill Calculator

Find when your prescription will run out and the earliest date you can usually refill it.

Date filled	2026-11-12
Quantity dispensed	90 tablets or units
Taken per dose	1
Doses per day	1
Insurer refill threshold	80 % used

Date filled

Quantity dispensed

tablets or units

Taken per dose

Doses per day

Insurer refill threshold

% used

Many insurers allow a refill after 75–80% of the supply is used

Runs out on

Wed, 10 February 2027

A 90-day supply at 1 a day. You can usually refill from Sat, 23 January 2027 (80% used). Order a few days early to avoid gaps.

Your supply

SupplyRefill allowed

About the Prescription Refill Calculator

Enter the fill date, the quantity dispensed, how many you take per dose and per day, and the share your plan requires to be used before a refill. The calculator gives the run-out date and the earliest likely refill date.

Days' supply is the quantity dispensed ÷ the amount you take per day. Pharmacies and insurers typically allow a refill once about 75–80% of the supply should have been used (earlier for some plans or vacation overrides; controlled substances are stricter). Take medicines as prescribed; this is a planning tool.

The formula

Days' supply = quantity ÷ (per dose × doses per day)

Worked example

90 tablets filled on 1 January 2026, one a day

Days' supply: 90
Runs out on 1 April 2026
Refill from about 14 March (80% used)

Questions people ask

Can I refill early for travel?

Many insurers allow a vacation override; ask your pharmacist.

Why is my refill date later?

Your plan may use a higher threshold, or count from the pickup date.