â Rectangle Calculator
Calculate area, perimeter, diagonal instantly from length, width.
How to use the Rectangle Calculator
- Enter Length, Width.
- The result updates instantly as you type.
- Copy or note down your result.
How it works
Formulas: Area = [Length]*[Width]; Perimeter = 2*([Length]+[Width]); Diagonal = hypot([Length],[Width]).
Example
Using the default values (Length: 8, Width: 5):
Area40
Perimeter26
Diagonal9.434
FAQ
Is the Rectangle Calculator free to use?
Yes. It is free, needs no signup and has no usage limits.
Is my data safe?
Yes. Everything is calculated in your browser, so what you type or upload is never sent to a server.
Can I use it on my phone?
Yes. KsWebProduction is built mobile-first and works in any modern browser.