MihsabaHow to use
The square calculator works in both directions. Start with side length, area, perimeter or diagonal, and the tool reconstructs the remaining measurements for the same square. This is useful when one measurement is known and you want the full geometry without manually rearranging formulas.
- Choose the measurement you know: side, area, perimeter or diagonal.
- Enter a positive value and choose the length unit.
- Calculate; the known value is normalized to side length.
- Review side, area, perimeter, diagonal, inradius and circumradius.
How it is calculated
Example
Example: a square with side 5 cm has area 25 cm², perimeter 20 cm and diagonal 5√2 ≈ 7.071 cm. Starting instead from area 25, perimeter 20 or that diagonal recovers the same 5 cm side.
Important notes
When area is the known value, interpret it in the squared version of the selected length unit, such as cm². Side, perimeter and diagonal remain ordinary length units. The model assumes an ideal square with equal sides and four right angles.
Frequently asked questions
Can I find the side from the diagonal?
Yes. Side = diagonal ÷ √2.
What is the inradius of a square?
It is half the side length because the inscribed circle touches the midpoint of each side.
How does the square diagonal relate to the circumcircle?
The square diagonal is the diameter of its circumscribed circle, so the circumradius is diagonal ÷ 2.
Is this calculator free?
Yes. It is free to use and requires no account.