Tangent Calculator
Calculate the tangent of an angle, and read it as a gradient or roof pitch.
Tangent is a gradient
tan 45° = 1, which is a 1-in-1 slope or 100% gradient. A road sign showing 10% is an angle of 5.7°, and a 6:12 roof pitch is tan⁻¹(0.5) = 26.6°. Tangent is undefined at 90° because the adjacent side reaches zero — a vertical line has no finite gradient.
The formula
tan θ = opposite ÷ adjacent = sin θ ÷ cos θ
Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.
How to use the Tangent Calculator
- Fill in each field with your own figures — the defaults are only there as an example.
- The result updates as you type, so there is no button to press.
- Check the breakdown under the main result for the supporting numbers.
- Use the copy button to take the result with you, or share the link to reload the same inputs.
Tangent Calculator — frequently asked questions
Is this tangent calculator free to use?
Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.
How accurate is the result?
The maths is exact for the formula shown on the page. Accuracy in the real world depends on your inputs and on assumptions the formula cannot see, so treat the output as a well-grounded estimate rather than a quote.
Can I use it on my phone?
Yes. The page is responsive, weighs a few kilobytes and works offline once loaded, so it behaves the same on a phone as on a desktop.
What people search for
This page answers each of these searches. They are the exact phrases visitors use to find the tangent calculator.
- tangent calculator
- slope from angle
- tangent function
- tan of an angle
- tan calculator
About this calculator
Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.
Last reviewed August 23, 2026 · Calculation runs client-side · No data collected · Report an error