Photo Print Aspect Ratios
Print sizes are aspect ratios in disguise: a 4×6 print is 3:2, an 8×10 is 5:4. If the print's ratio differs from your photo's ratio, something gets cropped — this chart shows what each common size is and what it does to a standard 3:2 camera photo.
| Print size | Ratio | Notes |
|---|---|---|
| 4×6 in | 3:2 | The classic snapshot print — matches most camera sensors exactly, no crop. |
| 5×7 in | 7:5 | Slight crop from a 3:2 original (the long edge loses about 7%). |
| 8×10 in | 5:4 | A noticeably squarer frame — a 3:2 photo loses about 17% of its long edge. |
| 8×12 in | 3:2 | Full-frame print with no crop; the "big 4×6". |
| 11×14 in | 14:11 | Between 5:4 and 4:3; expect a modest crop from 3:2. |
| 16×20 in | 5:4 | Same shape as 8×10, scaled up. |
| A5 / A4 / A3 paper | 1:√2 (≈1.4142) | ISO paper: every size is the previous one halved along the long edge, so the ratio never changes. A4 is 210×297 mm, which simplifies to 70:99. |
| Wallet print 2.5×3.5 in | 5:7 | The small portrait staple. |
How much gets cropped?
Crop loss depends only on the two ratios. Printing a 3:2 photo (ratio 1.5) on 5:4 paper (ratio 1.25): the height fills the paper, and the fraction of the width that survives is 1.25 ÷ 1.5 ≈ 83% — so about 17% of the long edge is trimmed away, split between the two sides. Keep faces and text out of the outer sixth of the frame if you plan an 8×10 of a 3:2 shot.
Working in pixels instead? The aspect ratio calculator simplifies any image size, and the 4:3 and 1:1 pages cover the other common camera shapes.
Frequently asked questions
Why do print labs offer both 8×10 and 8×12?
Because cameras and frames disagree: 8×12 keeps the full 3:2 camera frame, while 8×10 fits the older 5:4 frame standard. Same short edge, different long edge — check which one your frame expects before ordering.
What resolution do I need for a sharp print?
A common target is 300 pixels per inch: a 4×6 print wants about 1200×1800 px, an 8×10 about 2400×3000 px. Photos viewed from further away (posters) look fine at 150 ppi. Lab requirements vary, so treat these as working rules, not guarantees.