Inverse Tangent Calculator (tan⁻¹ / arctan) — Degrees & Radians

Calculate arctan (tan⁻¹) of any value. Get results in degrees, radians, gradians, and turns. Includes atan2 mode, common values table, and visual range indicator.

Find the angle whose tangent is x
Result (degrees)
45.000000°
arctan(1.0000) in degrees
Result (radians)
0.785398 rad
Angle in radians — most common in calculus and physics
Result (gradians)
50.000000 gon
Gradians — 400 gon = full circle, used in surveying
Result (turns)
0.125000
Fraction of a full rotation (1 turn = 360°)
Verification: tan(result)
1.000000
Should equal the input value (1.0000)
Quadrant
I
Angle falls in quadrant I (45.0° normalized)
Slope Interpretation
100.00% grade
A line at 45.00° has 100.00% grade (rise/run × 100)
General Solution
45.00° + n·180°
n = …, -315.0°, -135.0°, 45.0°, 225.0°, 405.0°, …

Arctan Range Indicator

Principal range: (−90°, +90°) | Result: 45.0000°
−90°−45°45°90°

General Solutions (first 5)

-315.00°
-135.00°
45.00°
225.00°
405.00°

Common Inverse Tangent Values

ExpressionInputDegreesRadians
arctan(0)0.000000.00000
arctan(1/√3)0.5773530°0.52360
arctan(1)1.0000045°0.78540
arctan(√3)1.7320560°1.04720
arctan(−1/√3)-0.57735−30°-0.52360
arctan(−1)-1.00000−45°-0.78540
arctan(−√3)-1.73205−60°-1.04720
arctan(0.5)0.5000026.57°0.46365
arctan(2)2.0000063.43°1.10715
arctan(10)10.0000084.29°1.47113
arctan(100)100.0000089.43°1.56080
arctan(∞)90°1.57080
Planning notes, formulas, and examples

About the Inverse Tangent Calculator (tan⁻¹ / arctan) — Degrees & Radians

The **Inverse Tangent Calculator** computes arctan(x) — the angle whose tangent equals x — and returns the result in degrees, radians, gradians, and turns. The arctan function is essential for converting a ratio or slope into an angle, one of the most common operations in trigonometry, physics, and engineering.

The standard arctan function returns values in the range (−90°, 90°), but many applications require a full four-quadrant angle. This calculator offers an **atan2 mode** that takes both a y-value and an x-value to return an angle in the full (−180°, 180°] range, correctly placing the result in the appropriate quadrant.

For each result the tool shows the general solution — all angles sharing the same tangent — using the formula θ = arctan(x) + n·180° for any integer n. It also verifies correctness by computing tan(result) and showing that it equals the original input.

The calculator includes preset buttons for common inverse tangent inputs, a visual indicator showing where the result falls within the arctan range, and a comprehensive reference table of standard arctan values. Whether you need to convert a slope to a heading, find a phase angle in electronics, or check an answer on a trig exam, this calculator handles the full conversion clearly.

When This Page Helps

Inverse Tangent Calculator (tan⁻¹ / arctan) — Degrees & Radians helps you avoid repetitive setup mistakes when solving trigonometric and coordinate-geometry problems. Instead of recalculating conversions, signs, and edge cases by hand, you can test inputs immediately, inspect intermediate values, and confirm final answers before submitting work or using numbers in downstream calculations. It surfaces key outputs like Result (degrees), Result (radians), Result (gradians) in one pass.

How to Use the Inputs

  1. Enter the required inputs (Mode, Value (x), y value).
  2. Complete the remaining fields such as x value, Decimal Precision.
  3. Review the output cards, especially Result (degrees), Result (radians), Result (gradians), Result (turns).
  4. Compare the result with the formula, diagram, or example values to catch sign, unit, or rounding mistakes.
Formula used
arctan(x) returns θ such that tan(θ) = x and −90° < θ < 90°. atan2(y, x) returns θ in (−180°, 180°] identifying the correct quadrant. General solution: θ + n·180° for any integer n.

Example Calculation

Result: 45°

Using value=1, unit=degrees, the calculator returns 45°. This example mirrors the calculator's live computation flow and is useful for checking manual steps and unit handling.

Tips & Best Practices

  • arctan always returns a value between −90° and +90° (exclusive).
  • Use atan2(y, x) when you need a full-circle angle, e.g., for bearings or polar coordinates.
  • arctan(0) = 0°, arctan(1) = 45°, arctan(√3) = 60°.
  • For very large x, arctan(x) approaches 90°; for very negative x, it approaches −90°.
  • The derivative of arctan(x) is 1/(1 + x²), which appears in integration tables frequently.

What This Inverse Tangent Calculator (tan⁻¹ / arctan) — Degrees & Radians Solves

This calculator is tailored to inverse tangent calculator (tan⁻¹ / arctan) — degrees & radians workflows, including common input modes, unit handling, and special-case behavior. It is designed for fast checking during homework, exam preparation, technical drafting, and coding tasks where trigonometric consistency matters.

How To Interpret The Outputs

Use the primary result together with supporting outputs to verify direction, magnitude, and validity. Cross-check against known identities or geometric constraints, and confirm that angle ranges, sign conventions, and domain restrictions are satisfied before using the numbers elsewhere.

Study And Practice Strategy

A reliable way to improve is to solve once manually, then verify with the calculator and explain any mismatch. Repeat this on varied examples and edge cases. The built-in preset scenarios for quick trials, comparison tables for side-by-side validation, visual cues that make trends and quadrants easier to read help you build pattern recognition and reduce sign or conversion errors over time.

Sources & Methodology

Last updated:

Frequently Asked Questions

  • Arctan is the inverse tangent function. Given a value x, arctan(x) returns the angle whose tangent is x, restricted to the interval (−90°, 90°).