Interval Ratio Calculator
Enter two frequencies (or note names) to instantly get the frequency ratio, cents value, and musical interval name.
Use the Interval Ratio Calculator
Enter Two Frequencies
Hz
Hz
Quick Examples
Enter two frequencies and click Calculate
Interval
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Ratio (f2/f1)
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Cents
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1200 per octave
Semitones
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12 per octave
Ratio Comparison
Equal Temperament
—
2^(n/12) — standard tuning
Just Intonation
—
Nearest simple whole-number ratio
Actual Ratio
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Exact f2 ÷ f1 from your input
Deviation from ET
0 cents
−50 ¢
0 ¢ (ET)
+50 ¢
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Summary
The Interval Ratio Calculator converts any two frequencies into a frequency ratio, cents value, and identifies the closest musical interval name. It works with raw Hz values or standard note names (e.g. A4, C#5).
How it works
- Given frequencies f1 and f2, the ratio is f2/f1. Cents are computed as 1200 × log2(f2/f1). The closest standard equal-temperament interval is identified by rounding the cents value to the nearest 100-cent step.
Use cases
- Verify tuning accuracy by comparing a played frequency to the target note.
- Analyze microtonal intervals and detuning amounts in cents.
- Explore just-intonation ratios vs. equal-temperament for any interval.
- Understand harmonic relationships between overtone series partials.
- Cross-check synthesizer pitch modulation depths.
Frequently Asked Questions
Last updated: 2026-05-29 · Reviewed by Nham Vu