PHOTO PRINT SIZE
Photo print sizes, millimetres and pixels in one table.
Look up one-inch to 8-inch print dimensions and their 300 DPI pixel values, convert between millimetres and pixels, and see how large one photo can be printed at each DPI. Everything runs locally in your browser.
Common photo print sizes
| Size | Print size (mm) | Size (inches) | 300 DPI pixels | Typical use |
|---|---|---|---|---|
| Small 1-inch | 22 × 32 | 0.87 × 1.26 | 260 × 378 | Licences, resumes |
| 1-inch | 25 × 35 | 0.98 × 1.38 | 295 × 413 | ID photos, resumes |
| Large 1-inch | 33 × 48 | 1.30 × 1.89 | 390 × 567 | Passports, visas, student IDs |
| Small 2-inch | 35 × 45 | 1.38 × 1.77 | 413 × 531 | Resumes, certificates |
| 2-inch | 35 × 49 | 1.38 × 1.93 | 413 × 579 | Certificates, work photos |
| Large 2-inch | 35 × 53 | 1.38 × 2.09 | 413 × 626 | Permits, passports |
| 3-inch | 55 × 84 | 2.17 × 3.31 | 650 × 992 | Album display |
| 5-inch (3R) | 89 × 127 | 3.50 × 5.00 | 1051 × 1500 | Photo printing, albums |
| 6-inch (4R) | 102 × 152 | 4.02 × 5.98 | 1205 × 1795 | Photo printing, frames |
| 7-inch (5R) | 127 × 178 | 5.00 × 7.01 | 1500 × 2102 | Albums |
| 8-inch (6R) | 152 × 203 | 5.98 × 7.99 | 1795 × 2398 | Mounting, large frames |
| A5 | 148 × 210 | 5.83 × 8.27 | 1748 × 2480 | Document printing |
| A4 | 210 × 297 | 8.27 × 11.69 | 2480 × 3508 | Document printing |
Click any row to load that size into the converter below. Pixels are millimetres ÷ 25.4 × DPI, rounded.
Millimetre and pixel converter
Millimetres to pixels
Pixels to print size
How large can one photo be printed?
| DPI | Typical use | Max print size (mm) | Max print size (inches) |
|---|---|---|---|
| 72 | Screen display / web | 104 × 146 | 4.10 × 5.74 |
| 96 | System icons / document preview | 78 × 109 | 3.07 × 4.30 |
| 150 | Everyday printing / submissions | 50 × 70 | 1.97 × 2.75 |
| 200 | Magazines and albums | 37 × 52 | 1.48 × 2.06 |
| 300 | Photo printing / ID photos | 25 × 35 | 0.98 × 1.38 |
| 600 | Professional printing | 12 × 17 | 0.49 × 0.69 |
For a 295 × 413 pixel photo: at 300 DPI it prints one-inch, at 72 DPI it would blow up to over ten inches but look visibly soft.
What can this tool do?
It settles the questions that usually get vague answers: how big is one inch, how large can this photo be printed at 300 DPI, how many pixels does a 6-inch photo need. The table lists the common ID photo and print sizes in millimetres, inches, 300 DPI pixels and typical use; the two converters move between millimetres and pixels, and the DPI table shows the maximum print size of one photo at each resolution so you do not pick the wrong DPI and end up with a soft print.
FAQ
What does 300 DPI mean?
DPI is the number of dots per inch. For one photo, a higher DPI means a smaller but sharper print: 72 DPI for screens, 150 DPI for everyday printing, 300 DPI for photo printing and ID photos, up to 600 DPI for professional press work. Raising the DPI does not add detail - it only packs the same pixels into a smaller area.
Why do ID photo pixel requirements differ slightly?
Because one inch is written as 25 × 35 mm or 2.5 × 3.5 cm depending on the source, and agencies may ask for 295 × 413 or 300 × 400. There is only one formula: pixels = millimetres ÷ 25.4 × DPI. Follow the exact pixel figures the receiving office gives you, and leave a little margin if you are unsure.
示例与注意事项Example & notes
一个例子A worked example
要冲印 6 寸照片：在表格里点一下「6 寸 (4R)」，换算器立刻给出 102 × 152 mm 与 300 DPI 下的 1205 × 1795 像素；再把手上这张图的像素填进右边的换算器，就能看它在 72 / 150 / 300 DPI 下分别能印多大。Planning a 6-inch print: click the 6-inch (4R) row and the converter instantly shows 102 × 152 mm plus 1205 × 1795 pixels at 300 DPI. Type your own photo's pixel size into the other converter to see how large it can be printed at 72, 150 and 300 DPI.
注意事项Things to watch
- 换算公式只有一条：像素 = 毫米 ÷ 25.4 × DPI。不同机构的一寸写法略有差别（25 × 35 mm 或 2.5 × 3.5 cm），像素要求因此会差几像素，提交前以受理方给的数值为准。There is only one formula: pixels = millimetres ÷ 25.4 × DPI. Agencies write one inch slightly differently (25 × 35 mm or 2.5 × 3.5 cm), so their pixel requirements differ by a few pixels. Follow the exact figures the receiving office gives you.
- DPI 越高，同样的像素能印的尺寸越小但越清晰。证件照与冲印一般要 300 DPI；把同一张图按 72 DPI 印会放大好几倍，但会明显发虚。The higher the DPI, the smaller and sharper the print from the same pixels. ID photos and photo printing want 300 DPI; the same file printed at 72 DPI comes out several times larger but visibly soft.
- 像素不够时不要靠插值放大充数：把 295 × 413 的图硬拉到 1205 × 1795，文件变大但细节不会变多，冲印出来照样模糊。正确做法是用更高分辨率的原片或重新拍摄。Do not fake extra resolution by upscaling: stretching a 295 × 413 image to 1205 × 1795 makes the file bigger, not the detail, and the print still looks soft. Use a higher-resolution original or reshoot instead.
- 打印店按毫米下单，软件按像素出图：自己排版时先把目标毫米数换算成像素（例如 A4 = 2480 × 3508 像素 @300 DPI）再放到画布上，出图尺寸才不会对不上。Print shops order in millimetres while software exports pixels: when you lay out a print yourself, convert the target millimetres to pixels first (A4 = 2480 × 3508 px at 300 DPI) so the exported size matches.
- 带透明背景的 PNG 冲印前先合成到白底或彩色底，否则照片店可能按白底处理；证件照要求纯色背景时，透明底会被判不合格。Flatten a transparent PNG onto a white or coloured background before printing, since labs often treat transparency as white; for ID photos that require a plain background, transparency is simply rejected.
相关问答More Q&A
5 寸、6 寸到底多大，能装进相册吗？How large are 5-inch and 6-inch prints, and will they fit an album?
5 寸 (3R) 是 89 × 127 mm，6 寸 (4R) 是 102 × 152 mm，7 寸 (5R) 是 127 × 178 mm，8 寸 (6R) 是 152 × 203 mm。常见相册卡位是 6 寸，7 寸以上通常要自己裁边或另配相框。5-inch (3R) is 89 × 127 mm, 6-inch (4R) is 102 × 152 mm, 7-inch (5R) is 127 × 178 mm and 8-inch (6R) is 152 × 203 mm. Album slots usually fit 6 inches, so 7 inches and above usually need trimming or a separate frame.
怎么让打印出来的照片不模糊？How do I keep prints sharp?
三个要点：一是按 300 DPI 导出（像素 = 毫米 ÷ 25.4 × 300），5 寸约需 1051 × 1500 像素；二是用 sRGB 色彩空间并关闭打印机的「图像压缩」选项；三是原始像素必须够用，不够就重拍而不是放大。Three things matter: export at 300 DPI (pixels = millimetres ÷ 25.4 × 300, so 5 inches needs about 1051 × 1500 px), use sRGB and turn off the printer image-compression option, and make sure the source resolution is high enough - reshoot instead of upscaling.