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Measurement Guides
Exact dimensions for everyday objects — in centimeters, millimeters, and inches. Each guide includes a size reference table, visual illustration, and a link to verify measurements on the ruler.
Credit Card Size in cm, mm & Inches
PopularExact ISO/IEC 7810 ID-1 dimensions: 85.60 mm × 53.98 mm. All units, comparison table, and FAQ.
A4 Paper Size in cm, mm & Inches
Popular210 × 297 mm. Full reference for A4, A3, A5 and all ISO 216 paper sizes in every unit.
Standard ID Card Size
NewNational IDs, driver's licenses, and access cards — all share the same ISO 7810 ID-1 standard.
iPhone Screen Size Comparison
NewPhysical screen dimensions in cm, mm, and inches for every iPhone model from 11 to 16 Pro Max.
How Many Pixels Is 1 cm?
NewThe answer depends on your screen PPI. Reference table for every common display + the formula.
US Letter Paper Size in cm, mm & Inches
New8.5 × 11 inches (215.9 × 279.4 mm). Pixel sizes at 72, 96, 150, and 300 DPI. Comparison with A4, Legal, and Tabloid.
Passport Photo Size — All Countries
NewUS: 2×2 in (51×51 mm). UK/EU: 35×45 mm. Canada: 50×70 mm. Country-by-country table with pixel dimensions for printing.
A3 Paper Size in mm, cm & Inches
New297 × 420 mm (11.69 × 16.54 in). Twice the area of A4. Full reference with pixel sizes at 72, 96, 150, and 300 DPI.
Ring Size Guide — US, UK & EU
NewFull conversion chart: US sizes 3–13, UK letters, EU circumference in mm, plus inner diameter for every size.
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