Wind chime and pan flute length calculator
Choose the lowest note, the scale and how many tubes you want. For wind chimes, enter the material, outside diameter and wall: the table gives each tube's length and where to drill the hanging hole. For a pan flute (or siku), enter the inside diameter and the air temperature.
Wind chime in 1″ × 0.065″ aluminum (C pentatonic)
6063 aluminum tube, 25.4 mm OD with a 1.65 mm wall, major pentatonic from C5, A 440 Hz; hole at 22.4% from each end.
| Note | Hz | Length (mm) | Hole (mm) |
|---|---|---|---|
| C5 | 523.3 | 537.9 | 120.6 |
| D5 | 587.3 | 507.7 | 113.8 |
| E5 | 659.3 | 479.2 | 107.4 |
| G5 | 784.0 | 439.4 | 98.5 |
| A5 | 880.0 | 414.8 | 93.0 |
| C6 | 1046.5 | 380.4 | 85.3 |
How to use it
- Choose Wind chime or Pan flute, the starting note, the scale and the number of tubes. The major pentatonic is the most used for chimes: any combination sounds good.
- For chimes, tap a hardware-store tube or enter your own measurements, taken with calipers. The fields are in millimeters (1″ = 25.4 mm).
- Tap Listen to hear the scale and Copy to take the cut list with you.
Help and explanations
A 1″ aluminum tube with a 0.065″ (1.65 mm) wall plays C5 (523.3 Hz) at 21.18″ (537.9 mm), drilled 4.75″ (120.6 mm) from each end.
The wind chime math
A hanging tube vibrates as a free-free beam: f = (4.730² ÷ 2πL²) · √(EI ÷ ρA), with E the material's stiffness, ρ its density, I the moment of inertia and A the cross-section area. Because L is squared, going up an octave takes 0.707 of the length, not half.
The point that barely moves sits at 22.4% of the length from each end; drilled there, the tube rings longest. It's the same math as Lee Hite's chime tables (leehite.org).
Materials
Stiffness and density come from MatWeb: 6063 aluminum (68.9 GPa, 2.70 g/cm³), EMT steel conduit (205 GPa), copper (117 GPa) and brass (110 GPa). PVC and bamboo vary a lot from tube to tube and show as estimates.
Pan flute and siku
Each pipe is closed at the bottom and sounds a quarter wavelength: L = c ÷ 4f − mouth correction, with c = 331.3 · √(1 + T ÷ 273.15), 343.2 m/s at 20 °C (68 °F). The correction is about 0.82 times the inside radius, as in Carrasquillo's bamboo measurements (Physics 406, University of Illinois).
Tips
- Cut each tube about 1/8″ (3 mm) long and tune it with the Lalatone tuner: trimming the end of a chime tube raises the pitch.
- On a pan flute, wax or a cork in the bottom raises the pitch. To lower it, you need a new pipe.
- Drill chimes with a 1/8″ to 5/32″ (3 to 4 mm) bit and deburr the hole so the cord doesn't fray.
Frequently asked questions
What lengths for wind chime tubes?
In 1″ × 0.065″ aluminum, C pentatonic: C5 21.18″ (537.9 mm), D5 19.99″ (507.7), E5 18.87″ (479.2), G5 17.30″ (439.4) and A5 16.33″ (414.8 mm).
Where do you drill the hanging hole on a wind chime?
At 22.4% of the length from the end: on a 21.18″ tube, 4.75″ (120.6 mm) in.
How much shorter is a tube one octave higher?
Multiply by 0.707: the 21.18″ C5 becomes C6 at 14.97″ (380.4 mm).
Does the material change the length?
A lot. For the same C5, 3/4″ EMT conduit gives 20.38″ (517.8 mm), 3/4″ copper 16.88″ (428.7 mm) and 20 mm PVC about 10″ (253.5 mm).
How long are pan flute pipes?
G4 (392 Hz) with a 15 mm inside diameter: 8.38″ (212.7 mm) from the rim to the bottom, at 20 °C. A4 with 14 mm: 7.45″ (189.3 mm).
Does temperature change the tuning?
On a pan flute, yes: from 68 to 86 °F (20 to 30 °C) the pitch rises about 29 cents. On a metal chime, hardly at all.