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Free
In-App Purchases
About
Instantly calculate all circle measurements from any single known value. Features include ring, arc, and sector calculations with detailed formulas and customizable input options. Offers a formula library and calculation history.
✓Instant calculation of all circle measurements
✓Ring (annulus) area and circumference
✓Arc, sector, and chord calculations
✓Detailed formulas with worked examples
✓Customizable input for pi and decimal places
✓Formula library and calculation history
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What's New in Circle Calculator
1.1.0
October 31, 2026
• Watch a short ad to try every Pro feature free for 1 hour • After setup, the Pro screen opens once with two clear plans. Close it and keep calculating for free • The Pro screen now explains the free trial: what you get today and when the first charge comes
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Subscriptions & In-App Purchases
Weekly Premium
Premium use without ads
$1.997 Days
3 Days trialEvents
New Ring and Arc tools, values on the circle
Oct 13, 2026 — Oct 27, 2026
User reviews
Developer apps
FAQ
What circle measurements can Circle Calculator find?
Circle Calculator can instantly find the radius, diameter, circumference, and area of a circle. It also calculates ring area, ring width, and circumferences for annuli, and arc length, chord, and sector area for arcs and sectors.
Does Circle Calculator show the formulas used for calculations?
Yes, every result in Circle Calculator comes with its formula and your numbers plugged in, allowing you to see exactly how the calculation was solved. This feature is available in the free version.
Can I input pi and square roots directly into Circle Calculator?
Yes, you can type pi (π) and square roots (√) directly into the input fields, such as '3π' or '5√3'. You can also use approximations like 3.14 or 3.1416, or full-precision pi.
What is the difference between the free and Pro versions of Circle Calculator?
The Pro version of Circle Calculator removes ads and unlocks advanced features like the rise (sagitta), sector area, segment area, and the Chord + Rise tool. It also provides unlimited history and a 'Copy All' function.
How much does Circle Calculator Pro cost?
Circle Calculator offers several subscription plans for Pro access: Weekly Premium at $1.99/P7D with a 3-day free trial, Monthly Premium at $4.99/P1M with a 3-day free trial, and Annual Premium at $24.99/P1Y with a 7-day free trial.
What is the update frequency for Circle Calculator?
The app was last updated on October 31, 2026, with version 1.1.0 released on February 5, 2022. This indicates a recent update, suggesting ongoing development and support.
What devices is Circle Calculator available on?
Circle Calculator is available on iPhone and iPad, supporting both portrait and landscape orientations. It also offers a Mac version.
Does Circle Calculator have ads?
The free version of Circle Calculator contains advertisements. The Pro version is ad-free.
