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SOHCAHTOA Calculator

Find a missing side or angle of a right triangle using SOH-CAH-TOA ratios.

About SOHCAHTOA Calculator

SOHCAHTOA is a mnemonic for the three primary trig ratios in a right triangle: Sin = Opposite/Hypotenuse, Cos = Adjacent/Hypotenuse, Tan = Opposite/Adjacent. Given any angle and one side, you can find any other side; given two sides, you can find the angle.

Formula

SOH-CAH-TOA

sin θ = O/H, cos θ = A/H, tan θ = O/A

O
Opposite side
A
Adjacent side
H
Hypotenuse
θ
Acute angle

Worked example

With the default values below, SOHCAHTOA Calculator returns Result of 5.773503. Change any input above and every figure here is recalculated in your browser.

Inputs used

Solve forone of Missing side (given angle + one side), Missing angle (given two sides)
Missing side (given angle + one side)
Known angle (degrees)accepts 0.01–89.99
30
Known side isone of Opposite, Adjacent, Hypotenuse
Adjacent
Known side lengthminimum 0.001
10
Find which side?one of Opposite, Adjacent, Hypotenuse
Opposite
First side isone of Opposite, Adjacent, Hypotenuse
Opposite
First side lengthminimum 0.001
5
Second side isone of Opposite, Adjacent, Hypotenuse
Hypotenuse
Second side lengthminimum 0.001
10

Results

Result
5.773503
Ratio used
opp = adj × tan(30°) = 10 × 0.57735

Step by step

  1. 1Identify the ratio= opp = adj × tan(30°) = 10 × 0.57735
  2. 2Result= opposite = 5.77350269

Assumptions and limits

  • The result is derived only from the 9 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What does SOHCAHTOA stand for?

SOH = Sine is Opposite over Hypotenuse, CAH = Cosine is Adjacent over Hypotenuse, TOA = Tangent is Opposite over Adjacent.

Can I use SOHCAHTOA for non-right triangles?

No — these ratios apply only to right triangles. For oblique triangles use the Law of Sines or Law of Cosines.

SOHCAHTOA Calculator | Calcrivo