Aspect Ratio Calculator - Reduce Screen Width and Height
Calculate the simplified aspect ratio from screen width and height, such as 16:9, 16:10, 21:9 or 4:3.
Quick answer
An aspect ratio calculator reduces width and height into a simple format such as 16:9, 16:10, 21:9, 3:2 or 4:3.
Method: ScreenTestKit generates the test surface in your browser. Results depend on visual inspection; the site does not read or diagnose physical panel hardware.
How to use this test
- Enter width and height using the same unit.
- Calculate the simplified ratio.
- Compare with common monitor, laptop, TV and video ratios.
- Use screen resolution values if you want the full display ratio.
What to watch for
- Browser viewport ratio may differ from physical screen ratio.
- Ultrawide marketing names are often approximate.
- Some laptops use productivity ratios such as 16:10 or 3:2.
- Video and screenshot dimensions can have different ratios.
How to interpret results
16:9
Common for TVs, many monitors and video.
16:10 or 3:2
Often used on laptops and productivity displays with more vertical space.
21:9 or wider
Usually an ultrawide format; exact ratios may vary by resolution.
Frequently asked questions
Can I use pixels or centimeters?
Yes. Any consistent width and height units work.
Why is my ultrawide not exactly 21:9?
Many product labels are rounded marketing names.