Circle area calculator, formulas, practical use.

Circle area and circumference calculations

The circle area calculator is designed for calculations of radius, diameter, circumference or area of a circle. For successful calculation, you need to know and enter into the calculator at least one of parameters. Then press send or enter to run calculations.

Circle parameters sketch:


Warning: Undefined array key "r" in /www/doc/www.webcalculators.net/www/wp-content/plugins/insert-headers-and-footers/includes/class-wpcode-snippet-execute.php(268) : eval()'d code on line 1

Warning: Undefined array key "d" in /www/doc/www.webcalculators.net/www/wp-content/plugins/insert-headers-and-footers/includes/class-wpcode-snippet-execute.php(268) : eval()'d code on line 2

Warning: Undefined array key "c" in /www/doc/www.webcalculators.net/www/wp-content/plugins/insert-headers-and-footers/includes/class-wpcode-snippet-execute.php(268) : eval()'d code on line 3

Warning: Undefined array key "a" in /www/doc/www.webcalculators.net/www/wp-content/plugins/insert-headers-and-footers/includes/class-wpcode-snippet-execute.php(268) : eval()'d code on line 4

Warning: Undefined array key "r" in /www/doc/www.webcalculators.net/www/wp-content/plugins/insert-headers-and-footers/includes/class-wpcode-snippet-execute.php(268) : eval()'d code on line 5

Warning: Undefined array key "d" in /www/doc/www.webcalculators.net/www/wp-content/plugins/insert-headers-and-footers/includes/class-wpcode-snippet-execute.php(268) : eval()'d code on line 5

Warning: Undefined array key "c" in /www/doc/www.webcalculators.net/www/wp-content/plugins/insert-headers-and-footers/includes/class-wpcode-snippet-execute.php(268) : eval()'d code on line 5

Warning: Undefined array key "a" in /www/doc/www.webcalculators.net/www/wp-content/plugins/insert-headers-and-footers/includes/class-wpcode-snippet-execute.php(268) : eval()'d code on line 5
area

Circle calculator form:

Circle calculator variables and constants explanation:

r – radius
C – circumference
d – diameter
A – area
π– 3,1415926535
– unspecified values
specified values
calculated values


Warning: Undefined array key "system" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/unit_system.php on line 2

Warning: Undefined global variable $_SESSION in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/unit_system.php on line 5

Warning: Trying to access array offset on value of type null in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/unit_system.php on line 5
Unit system:

Warning: Undefined array key "um1" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 5

Warning: Undefined array key "ui1" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 41

Warning: Undefined array key "um2" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 5

Warning: Undefined array key "ui2" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 41

Warning: Undefined array key "um3" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 5

Warning: Undefined array key "ui3" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 41

Warning: Undefined array key "um4" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 5

Warning: Undefined array key "ui4" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 41

Warning: Undefined array key "system" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 78

Warning: Undefined global variable $_SESSION in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 81

Warning: Trying to access array offset on value of type null in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 81

Warning: Undefined array key "um1" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 88

Warning: Undefined variable $um1mm in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 106

Warning: Undefined variable $um1cm in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 107

Warning: Undefined variable $um1dm in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 108

Warning: Undefined variable $um1m in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 109

Warning: Undefined variable $um1km in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 110

Warning: Undefined array key "um2" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 88

Warning: Undefined variable $um2mm in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 106

Warning: Undefined variable $um2cm in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 107

Warning: Undefined variable $um2dm in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 108

Warning: Undefined variable $um2m in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 109

Warning: Undefined variable $um2km in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 110

Warning: Undefined array key "um3" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 88

Warning: Undefined variable $um3mm in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 106

Warning: Undefined variable $um3cm in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 107

Warning: Undefined variable $um3dm in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 108

Warning: Undefined variable $um3m in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 109

Warning: Undefined variable $um3km in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 110

Warning: Undefined array key "um4" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 116

Warning: Undefined variable $um4mm2 in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 134

Warning: Undefined variable $um4cm2 in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 135

Warning: Undefined variable $um4dm2 in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 136

Warning: Undefined variable $um4m2 in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 137

Warning: Undefined variable $um4km2 in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 138

Warning: Undefined array key "r" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 196

Warning: Undefined array key "d" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 202

Warning: Undefined array key "c" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 208

Warning: Undefined array key "a" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 214
  • Warning: Undefined array key "r" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 224

    Warning: Undefined array key "d" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 224

    Warning: Undefined array key "c" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 224

    Warning: Undefined array key "a" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 224
    >
    Warning: Undefined variable $r in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 224
  • /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 225
    ">

  • Warning: Undefined array key "d" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 229

    Warning: Undefined array key "r" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 229

    Warning: Undefined array key "c" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 229

    Warning: Undefined array key "a" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 229
    >
    Warning: Undefined variable $d in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 229
  • /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 230
    ">

  • Warning: Undefined array key "c" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 234

    Warning: Undefined array key "a" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 234

    Warning: Undefined array key "r" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 234

    Warning: Undefined array key "d" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 234
    >
    Warning: Undefined variable $c in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 234
  • /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 235
    ">

  • Warning: Undefined array key "a" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 239

    Warning: Undefined array key "c" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 239

    Warning: Undefined array key "r" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 239

    Warning: Undefined array key "d" in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 239
    >
    Warning: Undefined variable $a in /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 239
  • /www/doc/www.webcalculators.net/www/wcs/Geometric_2D/Circle/circle_circumference.php on line 240
    ">

The formula for circle
circumference calculation:

Circle circumference formula

The formula for circle
area calculation:

Circle area formula

Circle calculator use:

Circle calculation is used in many industries and in a huge number of calculations. This is at least some of them:

  • perimeter of a tree trunk, limb, twig, stem, pipe, tube, hose, duct, wire, rod, cord, thread, rope, tunnel, pillar
  • cross-sectional area of a tree trunk, limb, twig, stem, pipe, tube, hose, duct, wire, rod, cord, thread, rope, tunnel, pillar
  • partial calculations of geometric shapes like cilinder, cone, sphere, barrel, torus and other rotational shapes
  • school calculations