G5 note frequency calculator
G5 is MIDI note 79, 10 semitones from A4. At the standard A4 = 440 Hz that puts it at 783.991 Hz.
- Period
- 0.001 275 53 s
- Wavelength in air
- 0.4375
- Quarter wavelength
- 0.1094
- One octave up
- 1567.9817 Hz
- One octave down
- 391.9954 Hz
- Equal-tempered fifth above
- 1174.6591 Hz
- Just fifth above
- 1175.9863 Hz
- How flat the tempered fifth is
- 1.9550 cents
- String length at that tension
- 0.0807
- MIDI note number
- 79
Show the working
- Reference pitch for A4 = 440
- Detune = 0
- Speed of sound = 343
- String tension = 80
- String mass per metre = 0.005
- semitones = 10 = 10
- Frequency = 440 * 2^(10/12) * 2^(0/1200) = 783.991
- Period = 783.991 > 0 ? 1/783.991 : 0 = 0.001 275 53
- Wavelength in air = 783.991 > 0 ? 343 / 783.991 : 0 = 0.437 505
- Quarter wavelength = 0.437 505 / 4 = 0.109 376
- One octave up = 783.991 * 2 = 1567.98
- One octave down = 783.991 / 2 = 391.995
- Equal-tempered fifth above = 783.991 * 2^(7/12) = 1174.66
- Just fifth above = 783.991 * 1.5 = 1175.99
- How flat the tempered fifth is = 1174.66 > 0 ? 1200 * log2(1175.99/1174.66) : 0 = 1.955
- String length at that tension = 783.991 > 0 ? sqrt(80 / 0.005) / (2 * 783.991) : 0 = 0.080 671 3
- MIDI note number = 79 = 79
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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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.
G5 at different concert pitches
| A4 reference | G5 frequency |
|---|---|
| 415 Hz | 739.446 Hz |
| 430 Hz | 766.173 Hz |
| 432 Hz | 769.736 Hz |
| 435 Hz | 775.082 Hz |
| 440 Hz | 783.991 Hz |
| 442 Hz | 787.554 Hz |
| 443 Hz | 789.336 Hz |
| 444 Hz | 791.118 Hz |
Frequently asked
What frequency is G5?
783.991 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.