Simple Desk Tools / Paper Size Converter

Paper Size Chart & Converter – A4, Letter, A5 in Pixels, mm, Inches

Pick any ISO, North American or photo size and see it in mm, cm, inches or pixels at your DPI. Runs entirely in your browser — nothing is uploaded.

Width–
Height–
Area–
Aspect ratio–
Also–

NameSeriesWidth mmHeight mmWidth inHeight inPx @ 300 DPI

Click a column heading to sort, a row to select that size.

In short: Paper Size Chart & Converter – A4, Letter, A5 in Pixels, mm, Inches is a free online tool with no sign-up and no upload — pick any ISO, North American or photo size and see it in mm, cm, inches or pixels at your DPI. Runs entirely in your browser — nothing is uploaded.

How to use

  1. Choose a size. Pick A4, US Letter, A5 or any other sheet from the list, or click a row in the chart below.
  2. Pick a unit. Switch between millimetres, centimetres, inches and pixels. For pixels, set the DPI you print or design at (300 DPI is the print standard, 96 DPI is the screen default).
  3. Compare. Select a second size to see the two overlaid at the same scale, so you can judge how much bigger A3 really is than Letter.

FAQ

What is A4 size in pixels?

A4 is 210 × 297 mm. At 300 DPI that is 2480 × 3508 pixels; at 150 DPI it is 1240 × 1754; at 72 DPI it is 595 × 842 pixels. Pixels depend entirely on the DPI, which is why this converter lets you set it.

What is the difference between A4 and US Letter?

A4 is 210 × 297 mm (8.27 × 11.69 in). Letter is 8.5 × 11 in (215.9 × 279.4 mm). Letter is slightly wider and noticeably shorter. A4 is the standard almost everywhere outside the USA, Canada and a few other countries.

How do ISO A sizes relate to each other?

Every A size has the same √2 aspect ratio (about 1:1.414). Folding a sheet in half across its long side gives the next size down, so two A5 sheets make one A4, two A4 make one A3, and so on. A0 has an area of exactly one square metre.

What are B and C series used for?

B sizes sit between A sizes and are common for posters, books and passports. C sizes are envelope sizes: a C4 envelope fits a flat A4 sheet, C5 fits A4 folded once (or a flat A5), and C6 fits A4 folded twice.

Simple Desk Tools vs. the usual suspects

This toolTypical "free" tool sites
PriceFree, foreverFree tier, then paywall
AccountNone — open the page and goSign-up or email required
Your filesStay on your device; nothing is uploadedUploaded to their servers, kept for hours
WatermarkNoneOn the free tier
LimitsNone — any size, any number of filesDaily caps and file-size limits
SpeedInstant — runs in your browserQueue, upload, wait, download

The no-bullshit promise: no registration, no upsell, no "premium" button, no watermark, no file limits, and your files never leave your computer. The site is paid for by a couple of ads, nothing else.

Privacy: this page is a static calculator. Nothing you enter is sent anywhere.