Aspect ratio calculator
Resizing without distortion means holding the ratio constant. The simplified ratio comes from the greatest common divisor.
New height
720.00
- Aspect ratio
- 1.777 778
- Simplified width term
- 16
- Simplified height term
- 9
- Scale factor
- 66.667 %
- New megapixels
- 0.922
Show the working
- Original width = 1920
- Original height = 1080
- New width = 1280
- Aspect ratio = 1920 / 1080 = 1.777 78
- New height = 1280 / 1.777 78 = 720
- divisor = gcd(round(1920), round(1080)) = 120
- Simplified width term = 120 > 0 ? round(1920) / 120 : 1920 = 16
- Simplified height term = 120 > 0 ? round(1080) / 120 : 1080 = 9
- Scale factor = 1920 > 0 ? 1280 / 1920 * 100 : 0 = 66.6667
- New megapixels = 1280 * 720 / 1e6 = 0.9216
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- new height = new width x original height / original width
1920 by 1080 simplifies to 16:9 because the greatest common divisor is 120.