About Angle Tools
About Us
Angle Tools is an independent suite of browser-based utilities for measuring, calculating and understanding angles, free to use and without accounts.
Our Mission
Measuring angles on a phone, tablet or workstation should not require an account or uploading a photo. Angle Tools provides practical geometric measurement and calculation in the browser, using device capabilities only when a tool needs them and you grant access.
Who runs Angle Tools
Angle Tools is an independent project run from India. It is not affiliated with any tool manufacturer, standards body or building authority, and the tools are free to use.
Questions, corrections and suggestions are welcome at hello@angletools.com
How the tools are checked
Every calculator works from formulas written out on its own page, and the code behind them is covered by more than 800 automated tests. The tests compare results with worked examples, textbook cases and published reference tables, such as standard crown-molding saw settings and the limits in the ADA Standards and the International Residential Code.
Building limits come from the published standards, name the section they are taken from and say which country they apply to. Readings from phone sensors and photos are estimates: each tool explains what limits its accuracy, and nothing here replaces a calibrated instrument for safety-critical work.
Core Principles
Honest Precision
Measurement tools show practical precision and, where available, an estimated uncertainty. Important work should still be checked with a calibrated instrument.
100% Client-Side Privacy
Photos, camera frames, and gyroscope readings never touch a server. All image rectification and angle calculations happen in local JavaScript memory.
Universal & Offline Access
Installable as an app, Angle Tools keeps the pages you have already opened working without a connection, in a basement, a workshop or on site. Full keyboard navigation and screen-reader readouts are built in.
Modern Web Standards
Built with static HTML, Canvas, SVG, WebRTC and DeviceOrientation APIs, so measuring happens in your browser.
Why We Built It
From woodworking and roof framing to physical therapy goniometry and architectural drafting, angle measurement is fundamental. Yet digital measuring tools are often inaccurate, filled with deceptive precision, or compromise user privacy by transmitting images off-device.
Angle Tools combines geometry, device sensors and optional perspective correction with a focused interface. The site is keyboard accessible, installable as a Progressive Web App, and designed to keep tool data on the device.
Start Measuring
Open any of our tools right now — free, instant, and with nothing to install.