G2 note frequency calculator
G2 is MIDI note 43, -26 semitones from A4. At the standard A4 = 440 Hz that puts it at 97.999 Hz.
- Period
- 0.010 204 2 s
- Wavelength in air
- 3.5000
- Quarter wavelength
- 0.8750
- One octave up
- 195.9977 Hz
- One octave down
- 48.9994 Hz
- Equal-tempered fifth above
- 146.8324 Hz
- Just fifth above
- 146.9983 Hz
- How flat the tempered fifth is
- 1.9550 cents
- String length at that tension
- 0.6454
- MIDI note number
- 43
Show the working
- Reference pitch for A4 = 440
- Detune = 0
- Speed of sound = 343
- String tension = 80
- String mass per metre = 0.005
- semitones = -26 = -26
- Frequency = 440 * 2^(-26/12) * 2^(0/1200) = 97.9989
- Period = 97.9989 > 0 ? 1/97.9989 : 0 = 0.010 204 2
- Wavelength in air = 97.9989 > 0 ? 343 / 97.9989 : 0 = 3.500 04
- Quarter wavelength = 3.500 04 / 4 = 0.875 01
- One octave up = 97.9989 * 2 = 195.998
- One octave down = 97.9989 / 2 = 48.9994
- Equal-tempered fifth above = 97.9989 * 2^(7/12) = 146.832
- Just fifth above = 97.9989 * 1.5 = 146.998
- How flat the tempered fifth is = 146.832 > 0 ? 1200 * log2(146.998/146.832) : 0 = 1.955
- String length at that tension = 97.9989 > 0 ? sqrt(80 / 0.005) / (2 * 97.9989) : 0 = 0.645 37
- MIDI note number = 43 = 43
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
Scenarios & local history
Compare a saved scenario
Recent calculations
The formula
- f = 440 x 2^((n - 69)/12), with n the MIDI note number
- one cent is 2^(1/1200), so a detune of c cents multiplies by 2^(c/1200)
- string frequency = sqrt(tension / linear density) / (2 x length)
Equal temperament divides the octave into twelve equal ratios of 2^(1/12), which is irrational. Every interval except the octave is therefore slightly out of tune against the simple whole-number ratios the ear prefers.
The tempered fifth is about 1.955 cents flat of a just fifth, which is close enough that almost nobody notices.
Concert pitch is not universal: many orchestras tune to 442 or 443 Hz, and baroque performance often uses 415.
G2 at different concert pitches
| A4 reference | G2 frequency |
|---|---|
| 415 Hz | 92.431 Hz |
| 430 Hz | 95.772 Hz |
| 432 Hz | 96.217 Hz |
| 435 Hz | 96.885 Hz |
| 440 Hz | 97.999 Hz |
| 442 Hz | 98.444 Hz |
| 443 Hz | 98.667 Hz |
| 444 Hz | 98.890 Hz |
Frequently asked
What frequency is G2?
97.999 Hz in equal temperament with A4 at 440 Hz.
How is the frequency of a note calculated?
Multiply the reference pitch by two raised to the number of semitones divided by twelve.