Circumference to Diameter Converter

Circumference

Output Unit

Decimal Places

π Value

Use Math.PI Custom π

Show radius and area

Your Name (optional)

Calculation Results

Diameter: –

Radius: –

Area: –

Formula: D = C / π

Using π = 3.141592653589793

Recent Calculations

No calculations yet. Enter values and click Calculate.

What is the circumference of a circle?

The circumference of a circle is the distance around the circle – the circle’s perimeter.

The formula is:

C=2πr

C=πd

where:

r = radius of the circle
d = diameter of the circle (d=2r)
π≈3.14159

Example:

If the radius r=7 cm

C=2πr = 2×3.14159×7≈43.98cm

How to calculate the diameter from the circumference?

To calculate the diameter of a circle when you know the circumference, use this formula:

D=C/π

where:

D = diameter
C = circumference
π≈3.14159

Example:

If the circumference C=31.4 cm:

D = 31.4/3.14159 ≈ 10cm

So, you just divide the circumference by π to get the diameter. or you can choose our Circumference to Diameter Converter to get your result instantly.