Calculator
What the Trigonometry Calculator does
Trigonometry Calculator: calculates sin, cos and tan from Angle and Unit. Example: angle 45 and unit Degrees gives sin 0.7071.
Enter Angle and Unit and the Trigonometry Calculator reports sin, cos and tan. Results refresh instantly, so trying variations costs nothing but a moment.
A second opinion on a calculation takes seconds and prevents errors compounding. That is usually what brings students checking homework here.
This runs client-side, which means we never receive what you enter and could not retrieve it if asked.
The meaning of each field, the formula in use, and a worked example that starts from the default inputs are all further down.
What do the Trigonometry Calculator fields mean?
The Trigonometry Calculator uses 2 inputs. A complete set of starting values is loaded for you, so nothing is required before the first result appears.
| Field | What to enter | Default |
|---|---|---|
| Angle | required | 45 |
| Unit | choose from Degrees or Radians | Degrees |
How does the Trigonometry Calculator work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same calculation.
Checks happen up front, so errors surface next to the form instead of hiding in the output.
Worked example
These are the values the Trigonometry Calculator loads by default, and the result it produces from them. This walkthrough uses the starting values, which means you can follow along without typing anything.
| Angle | 45 |
|---|---|
| Unit | Degrees |
| sin | 0.7071 |
|---|---|
| cos | 0.7071 |
| tan | 1 |
| What this means | sin/cos/tan for 45° |
Beyond the formula: sine, cosine and tangent
Sine, cosine and tangent all describe ratios of a right triangle’s sides relative to an angle, and the single most common calculator mistake is having the angle mode set to the wrong unit. Computing sin(30) in radians instead of degrees gives a completely different, correct-looking wrong answer.
Common mistakes and sanity checks
- A quick sanity check: sine and cosine are always between −1 and 1 for any real angle, no exceptions. If a computed sine or cosine falls outside that range, the input or calculation has an error somewhere.
- tan(90°) is undefined, because tangent is defined as sin/cos and cos(90°) is exactly zero. Calculators approaching this angle show enormous but finite numbers due to floating-point rounding, not the true undefined value.
- All three functions repeat every 360° (or 2π radians): sin(30°) and sin(390°) return the identical value, which is exactly why trigonometric functions are the standard tool for modelling anything cyclical, from sound waves to seasons.
How to use it
- Enter Angle.
- Pick a value for Unit: the options are Degrees or Radians.
- The result appears as you type. There is no button to press.
- You get sin, cos, tan and What this means back.
- Share the link rather than a screenshot. It carries the values with it.
What this tool does not do
- Displayed values are rounded; the underlying calculation keeps full precision.
- Very large or very small values reach the limits of floating-point precision, about 15 significant digits.
- Nothing is saved between visits, so keep your own record of anything you need again.
Frequently asked questions
2 things: Angle and Unit. Each field is pre-filled with a sensible default, letting you treat it as a what-if tool rather than a data-entry form.
With the values loaded when the page opens, sin comes out as 0.7071. Change a value and the number is recomputed on the spot.
No: there is no server involved. Close the tab and the values are gone.
It is free to use, with no premium tier holding back the useful parts.
It implements the published definition directly, without shortcuts or approximations.