Circle Length Calculator

If you want to learn how to calculate the length of a circle, our circle length calculator is the perfect tool 🎯. You can use this calculator to:

- Find the length of the radius of the circle.
- Calculate the length of the diameter of a circle.
- Find the length of the circumference.

Read on to learn more about how to find the length of a circle.

## Radius, diameter, and circumference: the circle length formula

Radius `r`

, diameter `d`

, and circumference `c`

are related. The higher the radius or the diameter, the higher the circumference. The circle length formula connects these variables in a single equation:

` c = 2πr`

If you only know the diameter, you can find the length of the radius of the circle by simply remembering the diameter is twice the radius:

`r = d/2`

Reordering the equations, you can also calculate the length of the circle diameter in terms of the circumference:

`d = c/π`

Similarly, you can know what the length of the radius of the circle is:

`r = c/(2π)`

## How to calculate the length of a circle?

Let’s suppose you want to know what is the length of the radius of a circle of 10 cm circumference. You can follow these steps:

- Use an adequate formula to solve your problem. In this case, it would be
`r = c/(2π)`

. - Input the circumference in the formula. The result should be:
`r = 10cm / (2π)`

. - Double-check your results. Input 10 cm in the circumference box of the circle length calculator. The result should also be 1.59155 cm for the radius.

## Other awesome circle-related calculators

Now that you know how to find the length of a circle, you can look at these other great tools and keep improving your skills:

- Circle calc: find c, d, a, r;
- Circle measurements calculator;
- Circle formula calculator;
- Radius of a circle calculator;
- Circumference to diameter calculator;
- Circumference and area of a circle calculator;
- Diameter of a circle calculator;
- Circle perimeter calculator;
- Square footage of a circle calculator; and
- Square inches of a circle calculator.

## FAQ

### What is the length of half a circle?

The length of half a circle is π (pi) times radius, expressed with the formula as chalf = πr or chalf = πd/2. It is the length of an ordinary circle divided by two in this case.

### What is the circumference of a 6-inch circle?

18.8496 inches. To find the circumference of any circle, multiply its diameter by π. In this instance:

- Take the circle’s diameter, which is
`6 in`

. - Multiply it by
`π`

. - The result is
`18.8496 in`

.