THD Percent
Compute total harmonic distortion in percent as 100 x sqrt(V2^2 + V3^2) / Vfundamental; harmonics must be non-negative and the fundamental positive.
Description
Compute total harmonic distortion in percent as 100 x sqrt(V2^2 + V3^2) / Vfundamental; harmonics must be non-negative and the fundamental positive.
THD Percent: Compute total harmonic distortion in percent as 100 x sqrt(V2^2 + V3^2) / Vfundamental; harmonics must be non-negative and the fundamental positive.
When to use THD Percent
Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.
- Fundamental (V)
- Required number input.
- 2nd harmonic (V)
- Required number input.
- 3rd harmonic (V)
- Required number input.
How THD Percent works
Compute total harmonic distortion in percent as 100 x sqrt(V2^2 + V3^2) / Vfundamental; harmonics must be non-negative and the fundamental positive. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.1
- THD (%)
- The resulting thd returned as a number.
Limitations and assumptions
- SNR, SINAD, THD, SFDR, and integrated-noise results require explicit bandwidth, weighting, reference amplitude, windowing, harmonic set, impedance, and RMS or peak conventions. Values measured under different conditions are not directly comparable.
- Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.
Alternative or Complementary approaches
Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.
References
-
Signal-to-noise ratio — Wikipedia contributors
Similar or alternative tools
- ADC Total Harmonic Distortion
Calculate THD from RMS harmonic amplitudes relative to the fundamental: sqrt(sum of harmonic squares)/fundamental. Output is percent and dBc; include only the harmonics specified by the measurement method, excluding noise and DC.
- THD+N Percent
Compute THD+N percentage from the RMS residual and fundamental as thdnPercent = sqrt(harmonicsAndNoiseV^2) / fundamentalV * 100.
- MDS Calculator
Compute the minimum detectable signal as MDS(dBm) = -174 + 10 x log10(BW(Hz)) + NF(dB) + SNR(dB); bandwidth must be positive and the noise figure non-negative.