Calculate Disc/Circle measurements

Calculate the Radius, Diameter, Circumference and Surface area of a Disc/Circle.
Fill in any of the boxes below to have all the other measurements instantly calculated.

r
2 × r
2 × π × r
π × r2

Good to know

See also

Calculation and conversion tools:

Text Conversions
Computation
Unit Conversions
international and imperial
Measurement
size, perimeter, area, volume...