To ensure a sharp print, your file should be set to 300 dpi.
You know the dimensions in centimetres, but don’t know how big your file needs to be in pixels? No worries — here’s how it works:
Just follow these two steps:
1️⃣ Divide the size in cm by 2.54 to convert to inches
2️⃣ Multiply the result by 300
🟩 Formula:
Pixels = (cm ÷ 2.54) × 300
Concrete example for a size of 6 × 4.5 cm at 300 dpi:
- 6 ÷ 2.54 = 2.36" → 2.36 × 300 = 708 px
- 4.5 ÷ 2.54 = 1.77" → 1.77 × 300 = 531 px
✅ Minimum file size: 708 × 531 pixels at 300 dpi
👉 Tip: the bigger your file (within reason), the better the print quality.
So go for “just a bit too big” over “just too small” 😄