Work out the area, perimeter and diagonal of a rectangle from its length and width. Locally, no upload, in your browser.
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
A rectangle is fully defined by its length and width. From these follow the area (length times width), the perimeter (two times length plus width) and the diagonal (the square root of length squared plus width squared, by the Pythagorean theorem). The diagonal is often the figure you actually want - for instance to check whether a screen, a piece of furniture or a picture fits through an opening.
The calculation runs entirely locally in your browser, in pure JavaScript - nothing is uploaded and nothing is stored. The calculator is unit-free: if you enter length and width in metres, the area is in square metres, and the perimeter and diagonal are in metres. A square is the special case with equal length and width. Change any input and everything updates instantly.
An honest note: this is a pure calculation helper for an ideal rectangle with right angles. It does not model skewed or distorted shapes (parallelograms, trapezoids). Results are shown rounded to two decimals; negative or empty inputs yield zero.
| Input formats | Form inputs (no file) |
|---|---|
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: A pure calculation helper for an ideal rectangle: area = length times width, perimeter = two times (length plus width), diagonal = sqrt(length² plus width²). Unit-free (area in square units). No skewed shapes. Rounded to two decimals.
No. The calculation runs entirely locally in the browser (pure JavaScript); nothing is sent or stored.
By the Pythagorean theorem: the square root of length squared plus width squared.
Yes. A square is a rectangle with equal length and width - just enter the same value twice.
In square units of your input: length and width in m give the area in m². The calculator is unit-free.