What this calculator does
Aspect ratio & screen size works out resize while keeping proportions, or find screen dimensions. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaNew height = new width × h/w; screen w = diagonal·r/√(r²+1) where r = aspect ratio
The inputs explained
| Field | What to enter |
|---|---|
| Original width | A number. Starts at 1920. |
| Original height | A number. Starts at 1080. |
| New width | A number. Starts at 1280. |
| Screen diagonal (inches) | A number, measured in inches. Starts at 27. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with original width
Every other input is held at the calculator’s starting values while original width varies. Select any row to load that scenario into the calculator.
How the answer changes with original width