Conversion
Paper Size Converter
View paper dimensions in mm, inches, cm, and pixels at various DPI. Covers A0-A6, Letter, Legal, Tabloid, and custom sizes.
How is this calculated?
Unit Conversions:
mm to inches: mm ÷ 25.4
mm to cm: mm ÷ 10
mm to pixels: mm × DPI ÷ 25.4
Area = width_mm × height_mm (in mm²)
Aspect ratio = width : height (simplified)
ISO 216 A-series:
A0 = 841 × 1189 mm (1 m² area)
Each An = A(n-1) halved on the long side
Aspect ratio always 1:√2
DPI reference:
72 DPI = screen/web
150 DPI = draft printing
300 DPI = standard quality print
600 DPI = high quality printFAQ
Frequently asked questions about paper sizes
What is A4 size in inches?
A4 is 210 × 297 mm, which equals 8.27 × 11.69 inches. It's slightly narrower and taller than US Letter (8.5 × 11 inches). A4 is the standard paper size in most countries outside North America.
What's the difference between A4 and Letter?
US Letter is 8.5 × 11 inches (215.9 × 279.4 mm). A4 is 8.27 × 11.69 inches (210 × 297 mm). Letter is slightly wider and shorter. This difference causes formatting issues when printing documents designed for the other standard.
How many pixels is A4 at 300 DPI?
At 300 DPI (print quality): A4 = 2480 × 3508 pixels. At 72 DPI (screen): 595 × 842 pixels. At 150 DPI (draft print): 1240 × 1754 pixels. Formula: mm × DPI ÷ 25.4 = pixels.
What is the ISO 216 standard?
ISO 216 defines the A-series paper sizes used internationally. Each size is half the area of the next larger size: A0 (1 m²) → A1 (0.5 m²) → A2 → ... → A6. The aspect ratio is always 1:√2 (≈1:1.414), allowing seamless scaling.
What paper size should I use for posters?
A3 (11.7 × 16.5 in) for small posters. A2 (16.5 × 23.4 in) for medium posters. A1 (23.4 × 33.1 in) for large posters. A0 (33.1 × 46.8 in) for very large displays. In the US, Tabloid (11 × 17 in) is common for small posters.
What DPI do I need for printing?
72 DPI: screen display only. 150 DPI: acceptable for large posters viewed from a distance. 300 DPI: standard print quality for documents, brochures, photos. 600 DPI: high-quality fine art prints and professional photography. Higher DPI = larger file size.