Aspect Ratio Calculator
Resize while keeping proportions exact.
Enter your values
Results update instantly as you type — no submit needed.
Results
- New height
- 720 px
- Aspect ratio
- 16:9
- Decimal ratio
- 1.7778
- Scale factor
- 0.6667×
Working
- 1h₂ = 1280 × 1080 ÷ 1920 = 720 px
Quick answer
To keep an aspect ratio, scale both dimensions by the same factor: new height = new width × original height ÷ original width.
h₂ = w₂ × h₁ ÷ w₁
How to use the Aspect Ratio Calculator
- 1Enter the original width and height.
- 2Enter the new width you want.
- 3Read the height that keeps the proportions.
Frequently asked questions
What is 16:9 in pixels?
Any size where width ÷ height is 1.778 — 1920×1080, 1280×720 and 3840×2160 are all 16:9.
Why does my image look squashed?
Because width and height were scaled by different factors. Always scale both by the same amount.