What is the circumference of a circle with diameter 2.25 inches

Here is the answer to questions like: how to find the perimeter of a circle with diameter 2.25 inches?

Circle Calculator

Circumference Area

Inputs:

Radius (r):		or
Diameter (d):		or
Area (A):
Unit of Lenght:

The circumference of a circle with diameter 2.25 is 7.069(*)

Formulas:

C = 2·π·r

C = π·d

C = √4·π·A

π = 3.1415
A = area of the circle
C = circumference or perimeter
r = radius, d = diameter

Step-by-step Solution:

Circumference of a cicle in terms of radius:

Circumference = 2·π·r = 2·3.14·1.13 = 7.04^(*)

In terms of diameter:

Circumference = π·d = 3.14·2.25 = 7.07^(*)

In terms of area:

Circumference C = √4·π·A = √4·π·3.98 = 7.04^(*)

^(*) 7.069 inches exactly or limited to de precision of this calculator (13 decimal places).

Note: for simplicity, the operations above were rounded to 2 decimal places and π was rounded to 3.14.

Use the this circumference length calculator above to find the perimeter of a circle given its diameter, or other parameters.

Formula to calculate the circumference of a circle

Here a three ways to find the circumference or perimeter of a circle:

Circumference length formula in terms of radius

C = 2·π·r

Circumference length formula in terms of diameter