Circle Calculator - Geometry

Circle Calculator is the most complete geometry calculator for students, teachers, engineers, and math enthusiasts. Solve any circle problem in seconds — from basic radius and diameter calculations to advanced arc lengths, sector areas, and sphere volumes. Whether you're doing homework, preparing for exams, or working on engineering projects, this app has every formula you need.

CIRCLE & GEOMETRY CALCULATORS
• Basic Circle: Calculate radius, diameter, circumference, and area instantly
• Arc Calculator: Find arc length, central angle, and arc area
• Sector Calculator: Compute sector area, perimeter, and angle
• Segment Calculator: Determine segment area, chord length, and height
• Chord Calculator: Calculate chord length, sagitta, and distance from center
• Annulus Calculator: Solve ring-shaped area and perimeter problems
• Polygon Calculator: Regular polygon area, perimeter, and interior angles
• Rotation Calculator: Surface area and volume of solids of revolution
• Tangent Calculator: Tangent line length and external point calculations
• Triangle Calculator: Area, perimeter, angles, and special triangle properties
• Sphere Calculator: Surface area and volume of spheres
• Cylinder Calculator: Surface area, volume, and lateral area of cylinders

25+ GEOMETRY TOOLS
• Formula Reference: Browse all circle and geometry formulas with visual diagrams
• Practice Mode: Test your skills with randomized geometry problems
• Unit Circle: Interactive unit circle with sine, cosine, and tangent values
• Construction Guides: Step-by-step compass-and-straightedge instructions
• History: Review past calculations and reuse them quickly
• Favorites: Save your most-used calculations for instant access

LEARN WHILE YOU CALCULATE
• Step-by-step solutions show every formula and intermediate result
• Visual circle diagrams update in real time as you type
• Gamification system with XP, achievements, daily streaks, and leaderboards
• Perfect for math homework, SAT/ACT prep, and university coursework

PRECISION & CUSTOMIZATION
• Adjustable decimal precision from 1 to 5 places
• Dark mode and light mode with Material Design 3
• Available in 10 languages: English, Turkish, Arabic, German, Spanish, French, Japanese, Portuguese, Russian, and Chinese
• Works on phones and tablets

PRO SUBSCRIPTION
Upgrade to Circle Calculator Pro to enjoy an ad-free experience. Focus on your calculations without interruptions. Pro unlocks the full power of every tool with zero distractions.

Free to download and use. All calculators and tools are available to every user.

Download Circle Calculator now and make geometry easy. From simple circle area calculations to complex sector and segment problems, every answer is one tap away.

Recent changes:
Maintenance update for Circle Calculator 1.8.1:
• Updated for Android 16 (API 36)
• Updated Google Play Billing to version 8
• Policy and compatibility updates
• Stability improvements