±Free
Circle measurements
Find diameter, circumference and area from a radius.
Enter a positive radius. The tool returns twice the radius, the circumference 2πr and the area πr²; lengths keep the input unit and area uses its squared unit.
How to use
- Enter your text, values, or image.
- Adjust the options and run the tool.
- Copy or download your result.
Worked example
Example input
Radius: 1
Example result
{
"diameter": 2,
"circumference": 6.28318530718,
"area": 3.14159265359
}Limitations and details
The radius must be positive; enter the radius rather than the diameter, and interpret output units yourself.
Inputs and options
- Radius
- Number · Minimum: 0
Frequently asked questions
Is this tool free and private?
Yes. All 300 tools are free in this phase. Processing happens in your browser; your input and files are not sent to our servers.