The formula
That is the whole thing. It is not a proprietary methodology and there is nothing clever about it. The reason we have a page for it is that the inputs need explaining and the caveats need stating, and because every figure on this site links here so you can see both.
A worked example, with real numbers
Here is the arithmetic for an Epson EcoTank, using figures we read on 27 September 2026.
- The printer takes the Epson 522 black ink bottle. Epson rates it at 4,500 pages against ISO/IEC 24712.
- That bottle was listed at $17.99 on Epson US on 27 September 2026.
- $17.99 ÷ 4,500 pages = $0.00400 per page, which is about 0.4 of a cent.
- For a color page, add three color channels. Each epson 522 color ink bottle was $17.99 rated at 7,500 pages, so the total comes to about 1.1 of a cent.
And the same steps for a laser: a Brother TN830XL high-yield toner cartridge rated at 3,000 pages at $98.29 on Brother USA gives about 3.3 cents a page.
| Supply | Rated yield | Price | Cost per page |
|---|---|---|---|
| Epson 522 black ink bottle | 4,500 pages | $17.99 | ~0.4¢ |
| Epson 522 black ink bottle + 3 × Epson 522 color ink bottle | ISO color page | $17.99 + 3 × $17.99 | ~1.1¢ |
| Brother TN830XL high-yield toner cartridge | 3,000 pages | $98.29 | ~3.3¢ |
All prices read 27 September 2026. These are illustrative calculations as at that date, not current prices.
What the ISO 5% coverage standard is
Every rated page yield in existence assumes a standardized test page with about 5% of its area covered in ink or toner. Toner Buzz describes that as roughly one third of a page of double-spaced text. The standards are ISO/IEC 24712 for inkjet and ISO/IEC 19752 and 19798 for monochrome and color laser.
The standard is genuinely useful: it is why a yield figure from Epson and one from Brother can be compared at all. It is also less ink than most real documents use. A page with a header image, a table with shaded rows, or a chart uses several times 5% coverage.
Why bottle ink is so much cheaper than cartridge ink
Not because the ink is different. Because of what it is sold in. A chipped cartridge is a small molded assembly with a chip, packaging and distribution, containing a modest volume of ink. A bottle is a bottle. A 170 mL Canon GI-21 bottle carries enough ink for 6,000 rated pages and costs about what a single high-yield cartridge does.
Toner sits in between: a dry powder in a cartridge with a delivery mechanism, which is why it lands at a few cents a page rather than a fraction of one.
Why color costs more, and how duplex helps
A black page draws one supply; a four-color page draws all four. So every inefficiency in the supply model is multiplied, which is why the gap between bottle and cartridge printing is widest on color and why published figures put cartridge color at about 20 cents a page.
Automatic two-sided printing halves your paper cost on any multi-page document. On a printer whose ink costs a fraction of a cent, paper is the larger line item — so a duplexer saves more than a cheaper bottle would. That is why we treat it as the one feature worth paying for regardless of budget.
What our figure does not account for
- Paper, unless stated. About a cent a sheet, and the same for every printer, so including it compresses the differences you are trying to see. The calculator lets you add it.
- The drum on a laser. A separate consumable, around 15,000 pages on the Brother models we cover. Most households never reach it; heavy users should count it.
- Maintenance ink on an inkjet. Print head cleaning consumes ink that never reaches paper. It is real, nobody itemizes it, and it is another reason to treat rated yields as optimistic.
- The printer itself. Sticker price amortized over the pages you print. This term is why a cheap laser beats an expensive tank printer at low volume. Our model pages include it in a separate total-cost table.
- Electricity. Lasers draw noticeably more when fusing. At household volumes it is a rounding error, so we leave it out rather than pretend to a precision we do not have.
The honest caveats, in one place
- Yields are manufacturer-rated, not measured by us. We have no lab. We are reproducing the manufacturer’s own claim and dividing by a price.
- Prices are dated, not live. There is no price feed on this site. Every figure is an illustrative calculation as at the date shown, never a current price. That is also why every buy button reads “Check price on Amazon” rather than showing a number.
- Your real cost will be higher, because of the 5% coverage assumption above.
- We use approximations and ranges deliberately. The tilde in “~0.4¢” is doing real work. We are publishing arithmetic on published inputs, not metered results, and a figure quoted to three decimal places would imply a precision we do not have.
- Where we could not source an input, we publish no figure. Two printers on this site have no cost per page for exactly that reason, and their pages say so.
Do it yourself
Find the exact supply your printer takes, look up its rated yield on the manufacturer’s page, note today’s price where you would actually buy it, and divide. Or let the calculator do it — it runs entirely in your browser, needs no sign-up, and shows the same working this page describes.