Aspect Ratio Calculator
Simplify any width × height to its ratio, match it against common display formats, and solve missing dimensions — with a live shape preview.
Simplify ratios and solve missing dimensions
Common display aspect ratios
Most desktop monitors are 16:9; premium laptops have moved to 16:10 and 3:2 for extra vertical space; ultrawides are 21:9 or 32:9; and modern phones range from 19.5:9 (iPhone) to 22:9. For the full pixel dimensions behind these ratios, see common screen resolutions.
Frequently asked questions
› How do I calculate an aspect ratio?
Divide width and height by their greatest common divisor. 1920 × 1080 both divide by 120, giving 16:9. The calculator above does this instantly and also matches your numbers against common display formats.
› Why does my phone's ratio look odd, like 19.5:9?
Phone panels stopped being 16:9 years ago. Manufacturers quote tall ratios against a base of 9 — 19.5:9, 20:9, 22:9 — because the numbers are easier to compare, even when the exact pixel ratio simplifies to something less readable.
› What aspect ratio should video be?
16:9 is standard for YouTube and TV. Vertical video for Shorts/Reels/TikTok is 9:16. Cinema masters are commonly 1.85:1 or 2.39:1.
› How do I resize while keeping the ratio?
Multiply the other dimension by the same factor. The 'solve a missing dimension' box above does it for you: enter the new width and it returns the height that preserves your ratio.
Related tools
- PPI Calculator Calculate PPI from resolution and screen size. Instant results with the formula worked through your numbers, plus physical dimensions and dot pitch.
- Common Screen Resolutions Reference list of common screen resolutions and viewport sizes across desktop, laptop, tablet and mobile, with aspect ratios and usage notes.
- Screen Size Comparison Compare phone, tablet, laptop and monitor screens as proportional overlays — or against your own screen. True-size mode shows devices at real physical size.
- Screen Resolution Checker Check your screen resolution instantly. See your display's pixel dimensions, available screen area and orientation, and learn what resolution means.