Circle from Circumference Table: Radius by Circumference
Reference table of radius for Circle from Circumference across a range of circumference values — exact, engine-computed figures you can read off at a glance.
Circle from Circumference Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Radius
5.0000
- Diameter
- 10.0000
- Area
- 78.5397
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Circle from Circumference Calculator
The Circle from Circumference Calculator works out your radius, along with 2 related figures in an instant. Enter circumference and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the circumference.
- Read off your radius, together with diameter and area — the calculator updates automatically, with no button to press.
Formula
The Circle from Circumference Calculator uses the formula:
Radius = Circumference ÷ (2 × 3.141592653589793)
Worked example
For example, with circumference of 31.4159 units, the radius is 5.0000.
| Circumference | 31.4159 units |
|---|
| Radius | 5.0000 |
|---|---|
| Diameter | 10.0000 |
| Area | 78.5397 |
Results are estimates for educational use, not professional advice.
Key terms explained
- Circumference
- The distance around the edge of a circle, equal to 2 × π × radius.
- Diameter
- The distance across a circle through its centre — twice the radius.
- Radius
- The distance from the centre of a circle or sphere to its edge.
- Area
- The amount of two-dimensional space a shape covers, measured in square units.
Frequently asked questions
Divide the circumference by 2π. A circumference of about 31.42 gives a radius of 5.
Use A = C² ⁄ 4π. A circumference of 31.42 gives an area of about 78.54 square units.
Divide the circumference by π. It is also simply twice the radius.
Because circumference is 2πr, reversing it to find the radius means dividing by 2π.
The Circle from Circumference Calculator uses the formula: Radius = Circumference ÷ (2 × 3.141592653589793). For example, with circumference of 31.4159 units, the radius is 5.0000.
Enter the circumference. Read off your radius, together with diameter and area — the calculator updates automatically, with no button to press.
Related guides
How to Calculate Circle from Circumference: Formula, Steps & Examples
Learn how to calculate Circle from Circumference — the formula explained step by step, with worked examples and a free calculator to check your answer.