How to use
- Enter the horizontal and vertical resolution in pixels, or press "This screen".
- Enter the diagonal in inches or centimeters, or pick a common screen from the list.
- Do not know the diagonal? Hold a bank card against the screen and move the slider until the outline matches the card exactly, then press "Use this measurement".
Frequently asked questions
What PPI is considered sharp?
At a desk (50–70 cm), around 110 PPI looks sharp to most people and 140+ PPI looks very crisp. Phones are held closer, so they need 400 PPI or more. The retina distance row shows from how far pixels stop being visible.
Why does "This screen" show a lower resolution than my monitor?
Browsers report the size in CSS pixels multiplied by the scaling factor. With some scaling settings or several monitors the value can differ from the panel resolution; enter the real resolution if you know it.
How accurate is the card method?
Usually within a few percent. All payment and ID cards share the same standard size (85.60 × 53.98 mm). Keep the card flat and look straight at it.