Find the simplified aspect ratio of any resolution, or calculate new dimensions while keeping the ratio intact — perfect for videos, images, and screen design.
Try:
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Aspect Ratio
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Original dimensions
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New dimensions — fill in one
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Resized Dimensions
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How to use
Get Ratio mode: Enter a width and height — the simplified ratio appears instantly (e.g. 1920×1080 → 16:9).
Common ratios are named automatically: Widescreen HD, Square, Portrait/Stories, etc.
Resize mode: Enter your original width and height, then fill in either the new width or new height.
The missing dimension is calculated for you to maintain the exact aspect ratio.
Use the presets to jump to common resolutions like Full HD, QHD, or Instagram square.
Frequently Asked Questions
What is a 16:9 aspect ratio?
16:9 means the width is 16 units for every 9 units of height. It's the standard ratio for HD and 4K TVs and most computer monitors. Common resolutions include 1280×720, 1920×1080, and 3840×2160.
How do I resize an image without stretching it?
Use the Resize mode — enter your original dimensions and one new dimension. The calculator gives you the correct value for the other dimension to preserve the ratio.
What is the aspect ratio of a standard TV?
Modern TVs use 16:9 (widescreen). Older CRT TVs used 4:3 (standard). Cinema screens often use 2.35:1 or 2.39:1 (anamorphic widescreen).
What does GCD mean in aspect ratios?
GCD stands for Greatest Common Divisor — the largest number that divides both dimensions. Dividing width and height by their GCD gives the simplest ratio form.
What is the aspect ratio of Instagram posts?
Instagram supports square posts (1:1), portrait (4:5), and landscape (1.91:1). Stories and Reels use 9:16.
Did you know?
The 16:9 ratio was chosen as a mathematical compromise between the most common cinema ratios (1.85:1 and 2.39:1) and TV ratios (4:3) — it's the geometric mean.
IMAX film uses a nearly square 1.43:1 ratio, requiring special projectors and cameras to capture and display the dramatically wider field of view.
Smartphone screens have moved toward taller ratios like 19.5:9 and 20:9, making most older widescreen content display with black bars on the sides.