Blog
Longer pieces than a tool page has room for: how a standard actually works, where the other calculators get it wrong, and why a tool here is built the way it is.
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One Equation Sets Every A4 Sheet at 210 × 297 mm. US Letter Has No Equation at All.
Why is A4 paper 210 x 297 mm? Two constraints fix every ISO sheet size exactly. US Letter was never derived from anything, which is why they never convert.
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Why Crochet Hook Sizes Are Such a Mess (And How to Actually Deal With It)
Crochet hook sizes have no single standard. Here's how three overlapping systems happened, why your G hook may not match mine, and how to buy hooks without guessing.
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Why '96 DPI' Is a Fiction Every Screen Still Pretends Is True
No screen is really 96 DPI. Here's the 1980s decision behind that number, why browsers can't detect your real resolution, and why on-screen rulers need calibration.