A DPI figure is either right or it is not. Here is how one gets checked before it goes on this site, and how it gets fixed if it turns out wrong.
Every pixel-and-DPI figure on PrintDPI traces back to one equation: pixels divided by target DPI equals inches printed, or the same equation solved for a different variable. Before a table or a written example goes live, the underlying multiplication is checked by hand against the calculator itself, using the same inputs a reader would type. If the two disagree, the page does not publish until they match.
The 300 DPI standard for photo printing, the 72 to 96 PPI range for screens, and the viewing-distance rules for large-format prints are long-standing conventions inside the printing and photo-finishing trade, not figures this site invented. Where a guide states a convention like that, it reflects what print labs and camera manufacturers commonly publish, not a single vendor's marketing claim.
Marcus Vance writes the guides, comparisons, and reference pages published under his byline; his background is on the authors page. Chris Terry owns this site and reviews what runs on it before publication, but does not write or byline the articles himself. That separation exists so the person checking a page for accuracy is not the same person who drafted it.
Where a guide links to a product, that link may be an affiliate link, disclosed in the footer of the page it appears on. A commission from a click never determines which product gets mentioned or what a guide recommends; the disclosure exists so a reader can weigh that possibility themselves.
If a figure, a formula, or a claim on this site is wrong, the fastest way to get it fixed is the contact form. A confirmed error gets corrected on the page directly, and the page's last-updated date reflects the change; PrintDPI does not quietly edit a page and leave the old date in place.
PrintDPI's calculators handle pixel and DPI arithmetic. They do not evaluate print quality, color accuracy, or paper choice, and nothing here substitutes for a conversation with an actual print lab about a specific job.