How to convert paper sizes (A4, Letter, and more)
US Letter into millimeters for an international print run, A4 into pixels for a 300 DPI canvas, points for a PDF page — paper-size conversion is really one table and a few constants. Pick the sheet and read every unit at once.
Step by step
Open the paper-size converter
Start the free converter — it covers A0–A6, US Letter, Legal, Tabloid, and Executive.
Choose the paper size
Select the sheet you are working with, such as A4.
Pick portrait or landscape
Landscape swaps the width and height of the same sheet — the physical size is unchanged.
Set a DPI for pixel dimensions
Enter a positive DPI such as 300 for print; pixels are inches × DPI, rounded to whole pixels.
Read every unit at once
A4 portrait comes back as 210 × 297 mm, 8.268 × 11.693 in, 595.28 × 841.89 pt, and 2480 × 3508 px at 300 DPI.
Tips that save a second try
The math is exact from nominal millimeters: inches are millimeters ÷ 25.4, points are inches × 72, and pixels are rounded to whole values because a raster canvas cannot hold a fraction.
Pixel dimensions cover the trimmed sheet only — add bleed, crop marks, and printer margins in your layout application.
Need a sheet outside A0–A6, Letter, Legal, Tabloid, or Executive (envelopes, B/C series)? Scale from the nearest preset's millimeter values.
Common questions
Why are pixel dimensions rounded?
A raster canvas must use whole pixels, while converting the exact physical dimensions at a chosen DPI often produces a fraction.
Does switching to landscape change the paper size?
No. It swaps the width and height of the same sheet; the physical area and preset remain unchanged.