Tools
True monthly cost
Quick answer
A month is 30.4375 days — 365.25 divided by twelve. Anything billed in weeks lands more often than a month does, so the charge and the advertised “monthly” price are not the same number. Enter the charge below and this works out which.
What the seller charges
True monthly costExample
$488.09per calendar month
$449.00 every 28 days — every 4 weeks.
| A full year of it | $5,857.04 |
|---|---|
| Times that charge lands in a year | 13.04 |
| Days each charge covers | 28 days |
$449.00 ÷ 28 days × 30.4375 days in an average month = $488.09
Gap — advertised low
$39.09 a month · $469.08 a year
Advertised as $449.00 a month. It really costs $488.09 a month — $39.09 more every month, and $469.08 more over a year.
What the tool is doing
It takes the amount that actually leaves your account, divides it by the number of days that one charge covers, and multiplies by 30.4375. That is the whole sum, and it is the same one the price index runs on every row it publishes. The working is printed under every answer so you can redo it yourself.
A four-week charge covers 28 days, not a month. Billed every four weeks, it lands 13.04 times a year rather than twelve, which is why $299 every four weeks costs $325.03 a month and $3,900.35 a year. Eleven weeks and twelve weeks look near enough identical on a checkout page and are not: $500 every eleven weeks is $197.65 a month, and the same $500 every twelve weeks is $181.18.
The gap
If the seller also quotes a monthly price, enter it and the tool names the difference in dollars per month and per year. A gap is not proof of bad faith — pricing in weeks and marketing in months is common and usually thoughtless rather than deliberate. It is still money, and it is still money nobody quoted you.
The gap runs the other way too. A seller who bills a prepaid three-month bundle sometimes advertises a monthly figure higher than the bundle works out to, and the tool says so in the same words.
What it cannot tell you
It knows nothing about what a seller includes for the money. Two figures that restate to the same monthly cost can differ on shipping, on consultation fees, on whether supplies are included, and on what happens to the price when your dose changes — which is what the course calculator is for. Price is one input among several, and the cheapest seller is not therefore the right one.
This tool calculates cost only. It is not medical advice, and no figure here is a recommendation to start, stop or change any medication.