Cents & Interval Calculator

Measure the interval between two frequencies in cents and as a ratio, name the nearest equal-tempered interval, and convert cents back to a frequency ratio. Runs in your browser.

Two frequencies


Interval between the two frequencies

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Ratio-
Nearest interval-

From cents → ratio-

Show the math

Cents are a logarithmic measure of pitch distance, 100 cents per semitone, 1,200 per octave:

cents = 1,200 × log₂(f₂ ÷ f₁)

The ratio is simply f₂ ÷ f₁, and any cents value converts back with 2^(cents ÷ 1,200). Useful for checking tuning offsets and just-intonation intervals.

Everything is calculated in your browser.

What this does

A cents and interval calculator measures the interval between two frequencies in cents and as a ratio, names the nearest equal-tempered interval, and converts cents back to a ratio.

How to use it

  1. Enter two frequencies.
  2. Read the interval in cents.
  3. See the nearest named interval.
  4. Or convert cents to a ratio.

How it works

A cent is a logarithmic pitch unit — 100 per semitone, 1,200 per octave. To go the other way, ratio = 2^(cents ÷ 1,200).

cents = 1,200 × log₂(f₂ ÷ f₁)

Understanding your result

Cents are a logarithmic measure, 100 to a semitone and 1,200 to an octave, which is why they compare pitch differences fairly across the whole range. The practical use is gauging how out of tune something is: a few cents is inaudible to most ears, around 5 to 10 starts to sound off, and the named nearest interval tells you what the ratio is in musical terms.

Example

440 Hz to 466.16 Hz is 100 cents — one semitone.

Sources & methodology

Last updated .

Frequently asked questions

What is a cent?

A cent is a logarithmic unit of pitch, 100 cents per semitone and 1,200 per octave. Between two frequencies, cents = 1,200 × log₂(f₂ ÷ f₁).

How is the nearest interval named?

The cents value is rounded to the closest semitone, named from the standard equal-tempered intervals, with any leftover cents shown as a + or − offset.

How do I convert cents to a ratio?

Use 2^(cents ÷ 1,200). Enter a cents value and the tool returns the matching frequency ratio.

Is anything stored?

No. Everything is calculated locally in your browser.