Spoke length calculator
Exact 3D-trig math, left and right computed separately, asymmetric rims handled, with a live hub view drawn to scale. Pick a hub and rim or enter the values manually.
New to the terms? Glossary → · Wheelbuilding fundamentals →
Hub0 in DB
Rim0 in DB
Hub
Left · non-drive
290mm
raw 290.9 mm · 16 spokes
Right · drive
290mm
raw 290.9 mm · 16 spokes
Build angles & tension
LRθ crossing67.5°67.5°γ bracing6.9°6.9°α flange-exit72.8°72.8°φ rim entry5.3°5.3°tension100%100%
Higher-tension side = 100%; the other is its share.
Show
lacing · face view · J-bend
leadingtrailingvalveLR
Open hub and rim database, validated against manufacturer specifications. Verify ERD and offset with the exact nipples you'll build with: that is where most length errors come from. Then cross-check against a second calculator and plan on a test build.