What is 5:4 Aspect Ratio?
5:4 gives 5 units of width for every 4 of height - a decimal of 1.25, the squarest landscape ratio still in daily use. Its portrait sibling 4:5 is the shape of classic 8×10 inch photographic prints and, in the social era, Instagram's tallest allowed feed post (1080×1350). In landscape it was the office-monitor standard of the 2000s (1280×1024 SXGA) and remains the shape of 4×5 large-format film beloved by landscape and portrait photographers. The extra height versus 3:2 and 4:3 suits vertical subjects: standing figures, headshots and architecture.
Common Uses for 5:4 Aspect Ratio
- 8×10 and 16×20 inch portrait prints
- Instagram portrait posts at 1080×1350 (4:5)
- 4×5 large-format film photography
- Legacy office monitors at 1280×1024
4:5 and the portrait print tradition
Portrait photography standardised on 4:5 because 8×10 paper was the professional print size: contact sheets, portfolios and framed portraits were all 4:5. That heritage is why Instagram capped feed posts at exactly 4:5 (1080×1350) - tall enough to dominate the feed, familiar enough to feel photographic. Cropping from a vertical DSLR file (2:3) to 4:5 costs 17% of the height; leave that margin around heads when shooting for print.