Trigonometry Calculator for Sin, Cos, Tan and Inverses
This trigonometry calculator evaluates sine, cosine, tangent and their inverse functions for any angle or value you enter. Type an angle and it returns the trig value instantly; type a ratio and the inverse functions return the matching angle.
Switch between degrees and radians with one tap, enter π expressions like π/4 in radian mode, and see exact values such as √2/2 for special angles alongside the decimal result. It is built for students learning trigonometry, engineers working with angles, and anyone who needs a quick trig answer without a full scientific calculator.
How to Use the Trigonometry Calculator
Pick a function
Use the tabs to choose sin, cos or tan to get a value from an angle, or arcsin, arccos or arctan to get an angle from a value.
Choose the angle mode
Tap DEG for degrees (such as 45, 90, 180) or RAD for radians. The calculator converts your input and shows the result in the unit you select.
Enter your value
Type a number in the input field. In radian mode you can also enter π expressions like π/4 or 2π/3. The result updates automatically as you type.
Read the result
See the primary value, an exact expression for special angles when one applies, plus related values — the reciprocal function and the angle in the other unit. Open Special Angles for a quick reference table.
Features
Six Trigonometric Functions
Calculate sin, cos and tan plus the inverses arcsin, arccos and arctan, all in one place via the tab navigation.
Degrees and Radians Support
Toggle between DEG and RAD instantly. Input is converted automatically and results display in your chosen unit.
Exact Values for Special Angles
For angles like 30°, 45° and 60°, see exact expressions such as 1/2, √2/2 and √3/2 next to the decimal.
Reciprocal Functions
Each result also shows the matching reciprocal — csc = 1/sin, sec = 1/cos and cot = 1/tan.
Real-time Calculation
Results refresh the moment you type, with no separate calculate button to press.
Input Validation
Arcsin and arccos accept only values from -1 to 1, invalid expressions show a clear message, and undefined results like tan(90°) display the infinity symbol.
Special Angles Reference Table
Open a collapsible table of sin, cos and tan values for common angles from 0° to 180° for quick lookups and verification.
Formula Reference
Each tab shows the relevant formula so you can see the mathematical relationship being calculated.
Frequently Asked Questions
How do I calculate sin, cos and tan of an angle?
Pick the sin, cos or tan tab, set the angle mode to DEG or RAD, and type the angle. The trig value appears instantly, along with the exact expression for special angles and the reciprocal function.
What is the difference between degrees and radians?
They are two ways to measure angles: a full circle is 360° or 2π radians. To convert, multiply degrees by π/180 for radians, or radians by 180/π for degrees. The calculator handles this automatically when you switch between DEG and RAD.
How do the inverse functions arcsin, arccos and arctan work?
Inverse functions work backwards: instead of turning an angle into a ratio, they turn a ratio into an angle. For example, if sin(30°) = 0.5, then arcsin(0.5) = 30°. Choose the arc tab, enter the value, and read the resulting angle in degrees and radians.
Why can I only enter values between -1 and 1 for arcsin and arccos?
Sine and cosine only ever output values from -1 to 1, so their inverses can only accept inputs in that range. No angle has a sine or cosine greater than 1 or less than -1, so anything outside the range shows a validation message.
Why does tan(90°) show infinity?
Tangent equals sin/cos, and at 90° the cosine is 0. Dividing by zero is undefined, so tan grows without bound as the angle approaches 90°. The calculator displays the infinity symbol (∞) here, and the same happens at 270°.
What are the trig values of special angles like 30°, 45° and 60°?
Special angles have values that can be written as simple fractions or square roots — for example sin(45°) = √2/2 ≈ 0.7071 and sin(30°) = 1/2. The calculator shows both the exact form and the decimal, and the Special Angles table lists 0° through 180°.
What are csc, sec and cot?
They are the reciprocal trigonometric functions: csc (cosecant) = 1/sin, sec (secant) = 1/cos and cot (cotangent) = 1/tan. When you calculate sin, cos or tan, the matching reciprocal appears as a related value.
How accurate are the calculations and can I use it offline?
Calculations use the browser's built-in double-precision math, accurate to roughly 15-16 significant digits, and results are shown to up to 10 significant figures. Because everything runs in your browser, the calculator keeps working without an internet connection once the page has loaded.
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