Math Calculators, Lessons and Formulas
It is time to solve your math problem
An online calculator that calculates the side, area, perimeter and diagonal of a rectangle
if you enter two known values. Step-by-step explanations
for each combination of input parameters are provided.
1. Input value you know and the value you want to find.
2. You can enter either integers (10), decimal numbers(10.12) or fractions(10/3)
Quick Calculator Search
Was this calculator helpful?
Please tell me how can I make this better.
Welcome to MathPortal. This web site owner is mathematician Miloš Petrović.
I designed this web site and wrote all the lessons, formulas and calculators.
If you want to contact me, probably have some question write me using the contact form or email me on