Bonsai Wire Size Calculator
Measure the branch at its thickest point where the wire starts and choose your wire type.
Result
- Wire diameter
- 2 mm aluminium
- One-third of branch
- 2 mm
- Wire length needed
- about 1.5x the branch length
Two thinner wires side by side often hold better than one thick wire. Check wire every few weeks in the growing season so it does not bite in.
How this calculator works
The one-third rule: wire diameter should be about a third of the branch diameter. Stiff branches move up a size and flexible ones down. Copper holds more for its size, so we suggest one step thinner than aluminium. Sizes snap to common wire gauges.