Protractor: Angle Measure

Content rating
Everyone
10+
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Content rating
Everyone
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About this app

Protractor is the most accurate digital protractor, angle ruler, and angle finder for Android. Measure any angle from 0 to 360° using your phone's gyroscope and screen — no analog tool needed.

Whether you're a student doing geometry homework, a craftsman setting miter cuts, or a designer measuring drawings, Protractor turns your phone into a precision angle measurement tool.

▶ MAIN FEATURES
• Protractor — measure angles between two screen points
• Angle ruler — touch two points to read the angle
• Gyroscope mode — measure physical angle by rotating the phone
• Plumb mode — vertical reference angle
• Pitch & roll mode — independent X/Y axis angles
• 0.1° precision via accelerometer + gyroscope sensor fusion
• Hold mode locks the value hands-free
• Switch units: degrees, radians, gradians
• Dark mode for indoor use
• Works fully offline — no account, no ads block

▶ HOW TO USE
1. Open Protractor and choose mode: screen touch or gyroscope
2. For screen mode: tap two points on the half-circle scale
3. For gyroscope mode: rotate the phone to measure
4. Read the angle in degrees, radians, or gradians

▶ WHO USES PROTRACTOR
• Students learning geometry and trigonometry
• Math teachers demonstrating angles in class
• Carpenters setting miter and bevel cuts
• Tile installers checking corner angles
• Roof installers calculating pitch
• Architects and designers measuring drawings
• Sewing pattern makers angling darts
• Quilters cutting precise triangle angles
• Engineers verifying mechanical part angles
• Hobbyists building model planes and trains
Updated on
May 25, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
This app may share these data types with third parties
App info and performance and Device or other IDs
No data collected
Learn more about how developers declare collection
Data is encrypted in transit