Spike's Calculators

Calculate the area and perimeter of a quatrefoil.

This calculator uses metres for measurements.

Quatrefoil = diameter of the four inscribed circles equal to the radius of the circumscribed circle

Quatrefoils come in different shapes. The calculations here are based on four circles inside a larger circle (see image)!

- the diameter of the circumscribed circle
- decimal precision, the number of digits after the decimal point

- the area of the circumscribed circle in square metres
- the area of the quatrefoil in square metres
- the area in square feet
- the area in square inches
- the perimeter of the quatrefoil in metres
- the perimeter in feet
- the perimeter in inches

A =r²+2 (𝛑r²/4) where A is the area of the quatrefoil r the radius of the circumscribed circle the quatrefoil's perimeter is equal to the circumference of the circumscribed circle

one metre (m) = 3.28083989501312 feet (ft) one metre (m) = 39.3700787401575 inches (in) one square metre (m²) = 10.7639104167097 square feet (ft²) one square metre (m²) = 1550.0031000062 square inches (in²)