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RatioCalc

Aspect Ratio Calculator

Lock a ratio, edit one dimension, the other solves instantly. 16 presets for video, social and cinema — plus the CSS snippet and 30 resolution lookups.

:

1920 × 1080

Exact ratio: 16:9 · CSS: aspect-ratio: 16 / 9 · padding-top fallback: 56.25%

Ratio calculators

What aspect ratio is…? (lookup by resolution)

People search by pixels — each lookup simplifies the pair via GCD, names the ratio, and preloads the solver.

Browse by fixed width or height

Start from one dimension — see every ratio’s partner instantly.

Widths — heights at every ratio

Heights — widths at every ratio

Print sizes — inches and cm at real DPI

Pixels to physical size: inches = pixels / DPI. See every resolution at print.

Platform guides — exact sizes

One page per platform with safe areas and export checklists.

Platform size reference

PlatformSizeRatio
YouTube thumbnail1280 × 72016:9
YouTube Shorts1080 × 19209:16
Instagram feed post1080 × 13504:5
Instagram story1080 × 19209:16
TikTok video1080 × 19209:16
X/Twitter card1200 × 67516:9

Compare ratios side-by-side

Same width vs same height — see letterbox and pillar sizes.

Frequently asked questions

How do I calculate height from an aspect ratio?

height = width ÷ (ratioW ÷ ratioH). For 1920 wide at 16:9: 1920 ÷ (16÷9) = 1080. The same formula works in reverse for width.

What is the modern CSS way to reserve 16:9 space?

Put aspect-ratio: 16 / 9 on the element. Legacy fallback: a padding-top: 56.25% wrapper with the content absolutely positioned inside. Pair with object-fit: cover.

Why does my video look squashed?

The player forced a different ratio than the content. Match them using the calculator, or letterbox with object-fit: contain so nothing stretches.

What aspect ratio is 1920×1080?

16:9. So is 1280×720, 2560×1440 and 3840×2160 — they all divide to 1.777:1. See the 1920×1080 lookup for the GCD math.

Privacy: ratio math runs entirely in your browser. Nothing you type is sent anywhere — the “copy” and URL-sharing encode only the numbers you entered.