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Aspect Ratio Calculator

Calculate aspect ratios, resize dimensions proportionally, or find the ratio from any width and height.

16:9
RATIO

Resize (Locked Ratio)

Common Presets

Aspect ratio is the proportional relationship between width and height, expressed as two numbers separated by a colon — like 16:9 (widescreen) or 4:3 (classic TV). It determines the shape of images, videos, and display screens.

Common aspect ratios include 16:9 (YouTube, most monitors), 9:16 (Instagram Stories, TikTok), 1:1 (Instagram posts), 4:5 (Instagram portrait), and 21:9 (ultrawide cinema). Knowing the ratio lets you resize content proportionally without distortion — changing one dimension automatically determines the other.

This tool calculates the missing dimension when you know the ratio and one side, finds the ratio from any width/height pair, and includes presets for all major social media and video platforms. Essential for designers preparing assets across multiple screen sizes and platforms.

This tool in other languages:

Français:
Calculateur de ratio d'aspect

Español:
Calculadora de relación de aspecto

Deutsch:
Seitenverhältnis-Rechner

Português:
Calculadora de proporção

日本語:
アスペクト比計算機

中文:
宽高比计算器

한국어:
종횡비 계산기

العربية:
حاسبة نسبة العرض إلى الارتفاع

Frequently asked questions

How do I calculate an aspect ratio from width and height?

Enter your current width and height — the ratio shows instantly. To resize, change either dimension and the other updates to maintain the ratio. Common presets (16:9, 4:3, 1:1, 21:9, IG Story, 4K, OG Image) are one click away.

What are the most common aspect ratios and where are they used?

16:9 — modern video, YouTube, TVs. 4:3 — older TVs, iPad, some photography. 1:1 — Instagram posts, profile photos. 9:16 — Stories, TikTok, Reels. 21:9 — ultrawide monitors and cinematic video. 3:2 — DSLR photography, prints.

What aspect ratio should I use for an Open Graph social media image?

1.91:1 is the standard for Open Graph images (Twitter/X, Facebook, LinkedIn share cards). At 1200×630 pixels, it renders well across all major platforms. Use the OG Image preset to lock this ratio, then verify in the OG Previewer.

How do I resize an image while keeping its aspect ratio?

Enter the original width and height to capture the current ratio. Then update either the new width or new height — the other dimension fills in automatically to preserve the ratio. Useful when you need a specific width but don't want to distort the image.

What's the difference between aspect ratio and resolution?

Aspect ratio is the shape (16:9, 4:3) regardless of size. Resolution is the actual pixel dimensions (1920×1080, 3840×2160). 1920×1080 and 1280×720 have the same aspect ratio (16:9) but different resolutions. Ratio matters for layout; resolution matters for sharpness.