About the Resonance Frequency Calculator
Resonant frequencies and harmonics of a string, open pipe or closed pipe.
Also known as: harmonic frequency, standing wave calculator, fundamental frequency, pipe resonance.
How to use this calculator
- Enter system, length, wave speed.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
Open: fₙ = n·v/2L · Closed: fₙ = n·v/4L (odd n only)
Worked example
Using the values pre-filled in the calculator above:
- System: String / open pipe (both ends)
- Length = 0.65 m
- Wave speed = 343 m/s
the calculator returns:
- Fundamental frequency: 263.85 Hz
- Wavelength of fundamental: 1.3 m