Calculate rectangle area.
GeometryOpen
Area of a Circle Calculator
Quick answer
If radius is 7, the area is 153.938 square units.
Circle area: Area = π × radius².
Enter your values
Area
153.938square units
The amount of flat surface this covers, in square units.
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About the Area of a Circle Calculator
The area of a circle is the surface it encloses, calculated from its radius. Enter the radius to find the area — for example, for a round table, a pipe cross-section, a garden bed or a pizza.
A circle with a radius of 7 has an area of about 153.94 square units.
Circle area
Area = π × radius²
π is approximately 3.14159.
Things to keep in mind
- The radius is half the diameter; halve the diameter before entering it.
- Doubling the radius makes the area four times as large.
- The answer is in square units of whatever unit you used for the radius.
See how the result changes
Each table re-runs this calculator with one value changed and everything else left as it is.
Area by radius
If radius goes from 7 to 10.5, area changes from 153.938 square units to 346.3606 square units (+125%).
| Radius | Area |
|---|---|
| 3.5 | 38.4845 square units |
| 5.25 | 86.5901 square units |
| 7start | 153.938 square units |
| 10.5 | 346.3606 square units |
| 14 | 615.7522 square units |
MATH GUIDE
A quick guide to Circle Area
Use it to get an accurate area in seconds — free, with no sign-up.
Instant results
See your area the moment you enter your numbers.
Free, no sign-up
Every calculator here is free to use, with no account required.
Accurate & transparent
The same standard formula runs on our server for every calculation.
How to Use the Circle Area Calculator
1
Enter Radius
Provide your radius.
2
View Your Results
Get your area instantly, calculated on our server.
What is Circle Area?
This math tool works out your area instantly, so you don't have to do the math by hand.
“One quick calculation, so you always know your area before you decide.”
What Affects Your Area
Your area depends on the values below.
Radius
Changing your radius changes your area.
Example Result
Here's what you can expect from a circle area calculation:
- Radius
- 7
- Area
- 153.938 square units
Frequently Asked Questions
- How does radius affect area?
- If radius goes from 7 to 10.5, area changes from 153.938 square units to 346.3606 square units (+125%).
- How to calculate circle area?
- Fill in radius in the Area of a Circle Calculator above and your area is calculated instantly. Change any value to see how the result responds.
- What does an example circle area calculation look like?
- If radius is 7, the area is 153.938 square units.
- Is this calculator free to use?
- Yes — every calculator on this site is completely free, with no sign-up or account required.
- How accurate is this calculator?
- It uses the standard formula and calculates on our server for every request, so results are precise for the values you enter.
- Is my data saved anywhere?
- No. Nothing you enter is stored or sent anywhere unless you choose to share a link with your values included.
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