Photo PrintPhoto size calculator: inches, mm and print pixels
By Mohamed Elatabany · Updated 3 October 2026
One inch is exactly 25.4 mm. Convert millimetres to inches by dividing by 25.4. To calculate a print-resolution target, multiply each dimension in inches by your chosen PPI.
Calculate your photo size
Calculated in your browser. No photo upload. Pixel targets describe resolution after cropping, not identity-document compliance.
Common photo sizes
| Size | Millimetres | Inches | Pixels at 300 PPI |
|---|---|---|---|
| 1 × 1 in | 25.4 × 25.4 | 1.000 × 1.000 | 300 × 300 |
| 2 × 2 in | 50.8 × 50.8 | 2.000 × 2.000 | 600 × 600 |
| 2 × 3 in | 50.8 × 76.2 | 2.000 × 3.000 | 600 × 900 |
| 4 × 6 in | 101.6 × 152.4 | 4.000 × 6.000 | 1200 × 1800 |
| 5 × 7 in | 127 × 177.8 | 5.000 × 7.000 | 1500 × 2100 |
| 35 × 45 mm | 35 × 45 | 1.378 × 1.772 | 414 × 532 |
| 33 × 48 mm | 33 × 48 | 1.299 × 1.890 | 390 × 567 |
| 50 × 70 mm | 50 × 70 | 1.969 × 2.756 | 591 × 827 |
Use the original units for exact printing
The table rounds decimal inches for readability. For a 35 × 45 mm print, enter 35 and 45 in millimetres in the app instead of entering rounded inch values. For a 2 × 2 inch photo, enter inches: 50 × 50 mm is a smaller rectangle.
How to calculate print pixels
For a 4 × 6 inch print at 300 PPI, multiply 4 × 300 and 6 × 300: 1200 × 1800 pixels. For 35 × 45 mm, divide by 25.4 first and multiply by 300: approximately 413.39 × 531.50, rounded up to 414 × 532 pixels.
Pixel dimensions do not decide the printed size
The same file can be printed at several physical sizes. Its PPI changes with the chosen dimensions and crop. Photo Print lets you set physical dimensions directly and check quality in the finished layout. See pixels, PPI and cropping.