Aspect Ratio Calculator
Reduce positive whole-number width and height dimensions to their simplest ratio.
01 / inputs
px
px
02 / result
SIMPLIFIED RATIO
16 : 9
- Ratio
- 16 : 9
- Decimal
- 1.77777778
Calculation trace
- gcd(1,920, 1,080) = 120120Greatest common divisor
- 1,920 ÷ 120 = 1616Simplified width
- 1,080 ÷ 120 = 99Simplified height
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How it works
Width and height are divided by their greatest common divisor (GCD) to give the simplest whole-number ratio, and the decimal width ÷ height is also shown.
Assumptions & limits
- Width and height are treated as integers for the reduced ratio.
- Height must be non-zero for the decimal form.
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FAQ
- Why is my ratio not 16:9?
- Only exact multiples reduce to 16:9. Slightly off pixel dimensions reduce to a different, larger ratio.
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Related calculators
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SOURCES
- World Wide Web Consortium (W3C)CSS Values and Units Module Level 4 ↗
Aspect ratio expressed as width:height reduced by the greatest common divisor
Accessed 2026-08-23