Pitch Shift Calculator
Shifting Pitch Without Losing the Math
Pitch-shifting a sample, vocal, or synth patch by "a few semitones" is easy to say and easy to get wrong by ear. Because equal temperament is logarithmic, each semitone up multiplies frequency by a fixed ratio rather than adding a fixed number of Hz — which means the same semitone shift produces a different Hz change depending on the starting pitch. This calculator applies the exact ratio so a shifted frequency lands precisely on the intended note.
The Formula
A positive semitone value shifts the pitch up; negative shifts it down. The calculator also reports the shift in cents, where 100 cents equal one semitone — the finer unit used for micro-tuning and detuning effects.
Where This Calculation Matters
- Vocal tuning and harmonization — generating a harmony line a fixed interval above or below a lead vocal starts from this exact ratio.
- Sample-based instruments — a sampler playing one recorded note across a keyboard shifts each key's playback rate using this formula to stay in tune.
- Time-stretching and pitch-correction plugins — understanding the underlying ratio clarifies what a plugin's semitone or cents control is actually doing to the signal.
- Detuning for width — subtle shifts of a few cents (fractions of a semitone) are used to fatten unison synth patches without sounding obviously out of tune.
| Semitones | Multiplier | Cents |
|---|---|---|
| +1 | ×1.059463 | 100 |
| +2 | ×1.122462 | 200 |
| +3 | ×1.189207 | 300 |
| +4 | ×1.259921 | 400 |
| +7 | ×1.498307 | 700 |
| +12 (octave up) | ×2.000000 | 1200 |
| −12 (octave down) | ×0.500000 | −1200 |
Computed from 2^(semitones/12); this is the fixed equal-temperament ratio used by every semitone-based pitch shifter.
How to Use This Calculator
- Enter the original frequency in Hz.
- Enter the number of semitones to shift — positive to shift up, negative to shift down.
- Select Calculate to get the new frequency in Hz, the exact frequency ratio applied, and the equivalent shift in cents.
Related Calculations
Look up a note's starting frequency with the Note Frequency Calculator, or measure the interval between two known frequencies with the Interval Calculator.