Circle with Radius 1
A circle with radius 1 has an area of π ≈ 3.1416 and a circumference of 2π ≈ 6.2832.
How to use this tool
- Enter radius in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your area and the full breakdown beneath it.
The unit circle (radius = 1) has area π and circumference 2π, fundamental constants in mathematics.
Frequently asked questions
- How do you calculate circle area and circumference?
- Area = π × r², Circumference = 2 × π × r, where r is the radius and π ≈ 3.14159.