Total Harmonic Distortion Calculator

Find THD from the fundamental and harmonic amplitudes.

Fundamental amplitude (V)

2nd harmonic (V)

3rd harmonic (V)

4th harmonic (V)

THD (%) 5.916

Formula: THD = sqrt(V2^2 + V3^2 + ...) / V1 * 100

Step-by-step with your numbers:

1. Values used:

2. Fundamental amplitude = 10 V

3. 2nd harmonic = 0.5 V

4. 3rd harmonic = 0.3 V

5. 4th harmonic = 0.1 V

7. THD = 5.916%

Did we solve your problem today?

THD measures how much harmonic content distorts a signal away from a pure tone.

The math behind it

THD = root-sum-of-squares of the harmonics divided by the fundamental, as a percentage.

Harmonics 0.5/0.3/0.1 on a 10 V fundamental give about 5.9%.

What is good THD?

Hi-fi audio aims for well under 1%; lower means a cleaner signal.