What is a Angle Converter?
> Angle Converter turns any angle between degrees, radians, gradians, arcminutes, and arcseconds. Enter a value, pick your units, and read the result with the exact formula shown. To convert degrees to radians, multiply by π/180 — so 180° = π rad, and 90° = π/2. It works offline. ---
### H2: Convert angles — degrees, radians, and gradians
Angles are measured in several units depending on the field. Everyday and geometry work uses degrees (°); trigonometry and higher maths use radians (rad); surveying uses gradians (gon); and astronomy and GPS use arcminutes (′) and arcseconds (″). This converter handles all five, so a degree value becomes radians, or a survey angle in gradians becomes degrees, in one step. Every result shows the exact formula, with a swap button and an all-units table.
The relationship to remember is that a full circle is 360° = 2π radians = 400 gradians. From that, 180° = π radians, so to convert degrees to radians you multiply by π/180 (about 0.0174533), and to convert radians to degrees you multiply by 180/π (about 57.29578). So one radian is about 57.3° — the angle at which the arc length equals the radius.
Because radians so often come out as tidy fractions of π, the tool shows the π-multiple wherever it's clean, not just a decimal: 30° is π/6, 45° is π/4, 60° is π/3, 90° is π/2, and 180° is π. That's usually the form students and engineers actually want, since π is irrational and its decimal (3.14159…) never ends.
A few honest notes. A radian is technically dimensionless — it's a ratio of arc length to radius — but it's treated as a unit for convenience. A gradian (or gon) divides the circle into 400 parts instead of 360, which makes right angles a round 100 gon; it's used mainly in surveying. And arcminutes and arcseconds are subdivisions of a degree (1/60 and 1/3600), used for very small angles in astronomy and navigation — despite the names, they're not related to time. Everything runs on your own device, offline, with nothing uploaded.
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