Aspect Ratio Calculator
Resize while keeping proportions exact.
Enter your values
ⓘ Live results
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.
Worked example
Using the values the calculator loads with:
Inputs
- Original width1920 px
- Original height1080 px
- New width1280 px
Results
- New height720 px
- Aspect ratio16:9
- Decimal ratio1.7778
- Scale factor0.6667×
- h₂ = 1280 × 1080 ÷ 1920 = 720 px
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.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.