What are the benefits of Trigonometry Calculator?

See all six trigonometric ratios (sin, cos, tan, csc, sec, cot) and principal inverse values simultaneously.. Switch between degrees and radians freely to compare the same angle in different notations.. Tooltips on each function provide domain and principal value range information for reference during study.. Undefined values are clearly marked, maintaining mathematical rigor while remaining intuitive.. Exact values such as √3/2 for 30°, 45° and 60°, plus a unit circle that shows the length and sign of sin and cos.. Work back from a value such as sin θ = 1/2 to every angle between 0° and 360°, typing fractions and roots as they are.. Solve a right triangle from two sides or an angle and a side, with working, and look up the 0-360° table on the same page..

Is Trigonometry Calculator free?

Yes, it is completely free to use, and no registration is required. Tool processing happens entirely in your browser, and your input content and uploaded files are not sent to a server. Our first-party improvement metrics use no cookies, visitor IDs, or session IDs and store only normalized page paths and daily counts for fixed event IDs.

Trigonometry Calculator

sin, cos, tan from an angle, angles from a value, and right-triangle sides — with exact values and a unit circle

角度を入力

角度

単位

sin・cos・tan の値から角度を求める

「1/2」「√3/2」のような分数やルートもそのまま入力できます。

関数

値

直角三角形の辺の長さと角度を求める

わかっている2つの値を選んで入力すると、残りの辺・角度・面積を途中式つきで計算します。

わかっている値

底辺 b

高さ a

三角関数表（0°〜360°・15°刻み）

sin・cos・tan の正確な値です。ルートや分数には小数第4位までの近似値を添えています。

角度	ラジアン	sin	cos	tan
0°	0	0	1	0
15°	π/12	(√6−√2)/4 (0.2588)	(√6+√2)/4 (0.9659)	2−√3 (0.2679)
30°	π/6	1/2 (0.5000)	√3/2 (0.8660)	√3/3 (0.5774)
45°	π/4	√2/2 (0.7071)	√2/2 (0.7071)	1
60°	π/3	√3/2 (0.8660)	1/2 (0.5000)	√3 (1.7321)
75°	5π/12	(√6+√2)/4 (0.9659)	(√6−√2)/4 (0.2588)	2+√3 (3.7321)
90°	π/2	1	0	定義されない
105°	7π/12	(√6+√2)/4 (0.9659)	−(√6−√2)/4 (-0.2588)	−(2+√3) (-3.7321)
120°	2π/3	√3/2 (0.8660)	−1/2 (-0.5000)	−√3 (-1.7321)
135°	3π/4	√2/2 (0.7071)	−√2/2 (-0.7071)	−1
150°	5π/6	1/2 (0.5000)	−√3/2 (-0.8660)	−√3/3 (-0.5774)
165°	11π/12	(√6−√2)/4 (0.2588)	−(√6+√2)/4 (-0.9659)	−(2−√3) (-0.2679)
180°	π	0	−1	0
195°	13π/12	−(√6−√2)/4 (-0.2588)	−(√6+√2)/4 (-0.9659)	2−√3 (0.2679)
210°	7π/6	−1/2 (-0.5000)	−√3/2 (-0.8660)	√3/3 (0.5774)
225°	5π/4	−√2/2 (-0.7071)	−√2/2 (-0.7071)	1
240°	4π/3	−√3/2 (-0.8660)	−1/2 (-0.5000)	√3 (1.7321)
255°	17π/12	−(√6+√2)/4 (-0.9659)	−(√6−√2)/4 (-0.2588)	2+√3 (3.7321)
270°	3π/2	−1	0	定義されない
285°	19π/12	−(√6+√2)/4 (-0.9659)	(√6−√2)/4 (0.2588)	−(2+√3) (-3.7321)
300°	5π/3	−√3/2 (-0.8660)	1/2 (0.5000)	−√3 (-1.7321)
315°	7π/4	−√2/2 (-0.7071)	√2/2 (0.7071)	−1
330°	11π/6	−1/2 (-0.5000)	√3/2 (0.8660)	−√3/3 (-0.5774)
345°	23π/12	−(√6−√2)/4 (-0.2588)	(√6+√2)/4 (0.9659)	−(2−√3) (-0.2679)
360°	2π	0	1	0

About Trigonometry Calculator

Trigonometric functions are essential in mathematics, physics, engineering, graphics, and signal processing, but mistakes often happen when degrees and radians are mixed or when undefined values are overlooked.

This calculator gives the six main trigonometric ratios and the principal inverse values in one view, making it easier to review standard angles and verify calculator or software output. It is especially useful when you need to compare several related values quickly without rewriting the angle in different forms.

If you only need to convert between degrees and radians, use the [Angle Converter](/en/calc/angle-converter/) to compare pi notation and degree-minute-second formats. For broader math work with powers, roots, and logarithms, use the [Scientific Calculator](/en/calc/scientific-calculator/). To compare trigonometry with logarithmic calculations, use the [Logarithm Calculator](/en/calc/logarithm-calculator/) as well.

For multiples of 15° such as 30°, 45° and 135°, exact values with fractions and roots (sin 30° = 1/2, cos 30° = √3/2) and pi notation (π/6) are shown, along with a unit circle that draws sin in red and cos in blue so you can see the signs at a glance.

The "angle from a value" section turns a value such as sin θ = 1/2 into every answer between 0° and 360° (30° and 150°) plus the principal inverse value. Decimals, fractions and roots like 1/2, √3/2 and -√2/2 can be typed as they are.

The right-triangle section takes any two of base, height, hypotenuse and angle and returns the remaining sides, angles, area and perimeter, with the formulas used at each step. A 0-360° table in 15° steps is at the bottom of the page.

How to use Trigonometry Calculator

Enter an angle and choose the unit: degrees (°) or radians (rad).
Click Calculate or modify the input to refresh all trigonometric values instantly.
When a value shows Undefined, hover over the info icon (ℹ) to see why that function is not defined for this angle.
Inverse function tooltips show the principal value ranges used (e.g., asin returns [-90°, 90°]). For multiples of 15°, exact values and a unit circle are shown as well.
To find an angle from a value, choose sin, cos or tan and type the value as 1/2, √3/2 or 0.5. Every answer from 0° to 360° is listed.
To solve a right triangle, pick what you know (base and height, angle and hypotenuse, and so on) and enter the two values. The remaining sides, angles, area and working appear.

Benefits of Trigonometry Calculator

See all six trigonometric ratios (sin, cos, tan, csc, sec, cot) and principal inverse values simultaneously.
Switch between degrees and radians freely to compare the same angle in different notations.
Tooltips on each function provide domain and principal value range information for reference during study.
Undefined values are clearly marked, maintaining mathematical rigor while remaining intuitive.
Exact values such as √3/2 for 30°, 45° and 60°, plus a unit circle that shows the length and sign of sin and cos.
Work back from a value such as sin θ = 1/2 to every angle between 0° and 360°, typing fractions and roots as they are.
Solve a right triangle from two sides or an angle and a side, with working, and look up the 0-360° table on the same page.