A ream of paper costs $6. A cartridge costs $24 and prints “about 300 pages.” Somewhere between those two numbers is what your printer actually charges you per page — and the industry has spent thirty years making sure you never do that division. PrintCost exists to do it.

Why a whole site for one formula

Because the formula is trivial and the inputs aren’t. “Cost per page” is cartridge ÷ yield + paper — three numbers, one division — yet every piece of it is hedged: yields are measured on an ISO test page most people have never seen, coverage is a concept nobody explains on the box, and the printer’s sticker price belongs in the comparison even though it never appears in a CPP figure. The calculator on the front page assembles all of it: cartridge math under the real ISO basis, coverage rescaling with its caveat printed next to it, paper and duplex, document and monthly volumes, and the inkjet-vs-laser crossover that decides which box to buy in the first place.

How the numbers are made

Every figure on the site comes from public, checkable arithmetic:

• Yield math follows the ISO/IEC yield standards (19752 for mono toner, 19798 for color toner, 24711 for inkjet) — the same tests cartridge makers cite — rescaled to your coverage with a linear model whose limits are stated wherever it’s used.
• Benchmark ranges in the articles come from dividing real street cartridge prices by rated yields, not from vendor claims.
• The breakeven solver is two TCO lines and an intersection — the kind of math that can be verified with a pencil, which is exactly the point.
• Filament conversions are geometry: cross-section × density, with the densities printed in the table.

Where a figure is an assumption — the 15% filament waste default, the 5%-coverage ISO basis — the page says so and lets you change it.

What this site leaves out

No printer reviews, no “top 10 printers of the year,” no brand recommendations, no affiliate links steering you toward a specific cartridge. The math doesn’t have a horse in the race; neither do the articles. What’s here instead: the formulas, the honest ranges, and a calculator that takes your prices and your yields — because the correct answer to “what printer should I buy” is almost always “the one whose consumables are cheapest for your volume,” and you can now compute that yourself.

Same workshop, different tools

PrintCost runs on nxtolerance.com next to sibling calculators — PowerBill for what appliances cost to run and EVCharge for what charging costs — same deal throughout: one page, honest math, nothing phoned home.

Corrections welcome

If a figure here contradicts arithmetic you can reproduce — a wrong density, a misstated ISO clause, a benchmark range that’s drifted — the contact page is the fastest way to get it fixed. Wrong numbers get corrected; they don’t get defended.