Print size and DPI converter
Convert pixels and millimetres at a chosen DPI, with paper-sized pixel counts, bleed sizes and pt / pica conversions.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Result
mm, cm, inches, pt, pica and pixels, plus full-page pixel counts and bleed sizes.
Enter a size to convert
DPI: 0
What this tool does
- Check whether a photo is printable: 3000 px at 300 DPI covers 10 in or 254 mm.
- Turn millimetre artwork into pixels: A4 needs 2480 × 3508 px at 300 DPI, or 2551 × 3628 px with 3 mm bleed.
- Convert typographic units: 1 in = 72 pt and 1 pica = 12 pt.
Example
Input
210x297
Output
300 DPI 下：210 mm → 2480 px 高度 297 mm → 3508 px 毫米 (mm) = 210 mm 厘米 (cm) = 21 cm 英寸 (in) = 8.267717 in 点 (pt) = 595.275591 pt 派卡 (pica) = 49.606299 pica 像素 (px) = 2480 px 含出血尺寸（每边 3 mm） = 216 mm 高度（mm） = 297 mm 高度（px） = 3508 px 含出血高度 = 303 mm 纸张整页像素与出血尺寸（每边 3 mm）： A4（210 × 297 mm） @ 300 DPI：2480 × 3508 px（含出血 2551 × 3579 px） A3（297 × 420 mm） @ 300 DPI：3508 × 4961 px（含出血 3579 × 5031 px） A5（148 × 210 mm） @ 300 DPI：1748 × 2480 px（含出血 1819 × 2551 px） B5（176 × 250 mm） @ 300 DPI：2079 × 2953 px（含出血 2150 × 3024 px） 名片（90 × 54 mm） @ 300 DPI：1063 × 638 px（含出血 1134 × 709 px） 6 寸照片（102 × 152 mm） @ 300 DPI：1200 × 1800 px（含出血 1271 × 1871 px） 出血是印厂防裁切偏差的余量：成品 210 × 297 mm 的 A4 通常按 216 × 303 mm 出图，再裁切成成品。
At 300 DPI, 3000 px = 254 mm = 10 in; the bleed adds 3 mm to each edge, the usual print-shop convention.
Frequently asked questions
Are DPI and PPI the same?
Strictly PPI describes the image and DPI the printer, but the terms are used interchangeably in print work. This tool follows the common “pixels ÷ DPI = inches” convention.
Why 3 mm of bleed on each edge?
Trimming is accurate to only 1–2 mm, so a file at exact finished size can show white edges. A 210 × 297 mm A4 is therefore output at 216 × 303 mm and trimmed down.
How are pixel counts rounded?
Pixels must be integers; millimetre-to-pixel conversion rounds to the nearest pixel, which keeps the whole sheet covered for typical sizes.
What DPI do I need?
300 DPI for standard print and photo labs, 150 DPI for large posters viewed from a distance, and 600 DPI for line art and fine books.
Keywords：印刷尺寸像素转毫米DPI 计算出血尺寸pt pica纸张整页像素A4 多少像素印刷分辨率