Enter a value to any field - the others are calculated themselves. If you change a value in any field, the others are automatically recalculated.
For decimals you can enter either points or commas
as decimal marks (but only one decimal point in a value).

r = m
d = m
C = m
A = m²
to 6 digits

The result will be in the units that you enter into the fields.
For example: if you enter millimeters, calculation will be also in millimeters.

If appears an error NaN, check whether you enter to the field
a correct value, ie. without any letters and other characters.


d = 2 × r [m]
C = π × d = 2 × π × r [m]
A = π × d²/4 = π × r² [m²]
Circle formula

d … diameter = 2 × radius

r … radius = ½ of diameter

S … center of circle

π (Pi) = 3,14 (about)

Calculation of circle online

Disk (mathematics) is the region in a plane enclosed by a circle.

Here you can find calculation perimeter of circle, circumference or calculation area of circle and disc, length of disc formula. Diameter from circumference, formula of diameter, area of disc from circumference. Function for perimeter of disc online. Formula for calculation of circle and for diameter, converter calculator.

Circle calculator


How to calculate ...

Bold shapes and objects are already in operation. The others contain only a formula.

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