Radius Calculator
Calculate the radius of a circle from different measurements
Circle Diagram
Formulas Used:
- From Diameter: Radius = Diameter ÷ 2
- From Circumference: Radius = Circumference ÷ (2π)
- From Area: Radius = √(Area ÷ π)
How to Use This Tool
This tool helps you calculate the radius of a circle. You can use one of three methods. Pick from Diameter, Circumference, or Area.
- Click the tab for your chosen measurement.
- Enter a positive number in the input box.
- Press the Calculate button.
- The results will appear below the input section.
Input Fields Explained
There are three input fields. Each one asks for a specific measurement:
- From Diameter: Type the circle’s diameter. The tool divides this value by two to find the radius.
- From Circumference: Enter the circle’s perimeter value. The tool divides it by (2 x π) to calculate the radius.
- From Area: Insert the circle’s area. The tool uses the square root of (Area ÷ π) to determine the radius.
Understanding the Output
The tool shows you four calculations:
- Radius: The distance from the center to the circle’s edge.
- Diameter: Twice the radius.
- Circumference: The total distance around the circle.
- Area: The surface space inside the circle.
Results appear with four decimal places. Use these numbers to compare measurements or check your work.
Notes and Limitations
This calculator works for perfect circles only. Remember to use consistent units. Enter only positive numbers. The formulas assume an ideal circle.
Common Use Cases
You can use this calculator for various tasks. It works well if you have a school project. It suits craft or design work. It can help when planning circular layouts too.
Final Remarks
This guide shows how to use the radius calculator easily. Follow the steps and review the output. It gives you all related measurements. Enjoy using the tool for your projects.