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RatioCalc

What aspect ratio is 1280×1024?

5:4 (~1.2500:1)

1280×1024 simplifies to 5:4 (GCD 256). In decimal that is ~1.2500:1 — a standard 5:4 frame used for legacy 5:4 lcds, industrial panels. The calculator below is preloaded to 5:4 so you can solve any partner dimension at the same ratio.

→ Open the full 5:4 Aspect Ratio Calculator →

:

1920 × 1536

Exact ratio: 5:4 · CSS: aspect-ratio: 5 / 4 · padding-top fallback: 80.00%

How the ratio was computed

GCD(1280, 1024) = 256

1280 ÷ 256 = 5 → 1024 ÷ 256 = 4

→ 5:4 (dec. 1.2500:1) · padding-top 80.00%

CSS: aspect-ratio: 5 / 4

All math is local and instantly invertible — swap width and height and the ratio stays the same, just rotated. URL sharing works: ?w=1280&h=1024 style deep-links still resolve via the ratio parameters.

Quick 5:4 partner table

WidthHeight (5:4)
640px512px
1280px1024px
1920px1536px
2560px2048px
3840px3072px

Other sizes in 5:4

No other catalogued sizes share 5:4 exactly — the table above covers the common computed variants.

Related lookups

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Tip: designing for 1280×1024 sxga 5:4? Master at 1280×1024 exactly, then export lighter proxies by halving both sides (e.g. 640×512) — the ratio stays 5:4 and downscales stay sharp.