Boneyard Tools

Harmonic Series Calculator

Enter a fundamental frequency in hertz and choose how many harmonics to list. The calculator multiplies the fundamental by 1, 2, 3 and so on to give each overtone frequency, and shows the interval each one sits above the root in cents. A fundamental of 110 Hz produces 220, 330, 440 and so on, letting you see the exact pitches an instrument or synth voice reinforces.

How to use the harmonic series calculator

  1. Type the fundamental frequency into the Fundamental field, for example 110 Hz.
  2. Enter how many harmonics to list in the Harmonics field, from 1 up to 64.
  3. Read the table: each row shows the harmonic number, its frequency in Hz, and the cents above the fundamental.
  4. Click Copy to grab every row as plain text, such as '3: 330 Hz (+1902 cents)'.
  5. Change either field to rebuild the series instantly; there is no submit button.

Examples

First eight harmonics of 110 Hz

Fundamental 110 Hz, 8 harmonics
110, 220, 330, 440, 550, 660, 770, 880 Hz

Octaves land on powers of two

Harmonics 2, 4 and 8 of any fundamental
1200, 2400 and 3600 cents above the root

Four harmonics of concert A (440 Hz)

Fundamental 440 Hz, 4 harmonics
440, 880, 1320, 1760 Hz

Frequently asked questions

What is the harmonic series?

It is the set of frequencies that are whole-number multiples of a fundamental. Harmonic n has frequency n times the fundamental, so a 100 Hz root gives 100, 200, 300, 400 Hz and onward. These overtones are what give a violin, trumpet or voice its distinctive timbre.

How is the cents value above the fundamental calculated?

For harmonic n the interval above the fundamental is 1200 times the base-2 logarithm of n, measured in cents. The second harmonic is exactly 1200 cents (one octave), the fourth is 2400 cents (two octaves), and the third is about 1902 cents.

Why does the third harmonic sound like a fifth?

The third harmonic sits about 1902 cents above the root. That is one octave (1200 cents) plus roughly 702 cents, which is a near-just perfect fifth. This is why brass and string overtones naturally outline major triads.

Are harmonics and overtones the same thing?

They are closely related but numbered differently. The fundamental is harmonic 1, and its overtones start above it: the first overtone is harmonic 2, the second overtone is harmonic 3, and so on. This tool numbers every partial from the fundamental as harmonic 1.

How many harmonics can I list?

Up to 64. The Harmonics field must be a whole number from 1 to 64; anything higher shows a limit message. High harmonics crowd together in pitch and, for a high fundamental, quickly climb past the roughly 20 kHz ceiling of human hearing.

What counts as a valid fundamental?

Any finite number greater than zero. If the field is blank, zero, negative or not a number, the tool shows a prompt to enter a fundamental greater than zero instead of a table. There is no upper bound on the frequency itself.

How precise are the frequency and cents values?

The engine keeps six decimal places internally, then the table rounds frequency to two decimals and cents to one decimal for readability. Whole-number fundamentals like 110 Hz produce exact integer harmonics, so no rounding is visible for them.

Is my input sent to a server?

No. The whole series is computed in your browser with plain arithmetic, so nothing you type is uploaded. The tool works offline once the page has loaded.

Can I use this for guitar or string overtones?

Yes. Enter the open-string frequency as the fundamental to see the natural harmonics you get by lightly touching the string at its halfway, third and quarter points, which correspond to harmonics 2, 3 and 4.

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