Screen Size Calculator
Enter a screen diagonal and pixel resolution to calculate active width, height, aspect ratio, pixel density and pitch, with a dimensioned screen diagram.
YOUR CALCULATION
Result
—
Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Assuming square pixels, the physical width-to-height ratio equals the pixel width-to-height ratio. Apply the Pythagorean relationship to the diagonal to find width and height. Divide the pixel diagonal by the physical diagonal in inches for pixels per inch.
W = D × horizontal / √(horizontal²+vertical²); H = D × vertical / √(horizontal²+vertical²); PPI = pixel diagonal / diagonal in inches
Worked example
A 24-inch active diagonal with 1920 × 1080 square pixels has a 16:9 aspect ratio, width about 53.13 cm, height about 29.89 cm and density about 91.79 pixels per inch.
Assumptions and input details
Use the active visible area, excluding the bezel. The model assumes a flat rectangular screen with square pixels. Physical PPI is not the same as CSS pixels, operating-system scaling, printer DPI or image-quality judgment. Portrait resolutions are supported. Actual manufacturer dimensions may differ due to rounding or a different active-area definition.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Find the diagonal of a right triangle or rectangle. Mix length units and compare 21 unit conversions with a triangle diagram.
Find real length, drawing length or a scale ratio. Mix length units and compare linear, area and volume scale factors with a size diagram.
Find transfer time, required nominal speed or data size. Distinguish bits, bytes, decimal and binary units and include an explicit effective-throughput percentage.
Reserved advertising space.