Heddle Calculator
Calculate heddles needed per shaft for loom threading. Plan heddle count from warp ends, shafts, and threading pattern for your loom.
Specialist tool for Weaving1 documented formula2 recommended next stepsPrivate in your browser
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A quick decision brief for this specific tool
Inputs that matter
Total Warp Ends, Number of Shafts, Threading
Output to expect
Heddles Per Shaft
How it works
1 documented formula across 1 calculation mode
- Confirm that every value uses the unit and time basis shown before comparing scenarios.
- Change one input at a time to see which assumption materially changes the result.
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Reference & details
How it works
Updated July 2026
How it works
Updated July 2026Equal Distribution
For straight threading (1-2-3-4 repeat), ends distribute equally. 400 ends on 4 shafts = 100 heddles per shaft.
Heddles per shaft = Total ends ÷ Number of shaftsPattern-Weighted Distribution
Complex twills and satin drafts thread unevenly. Read the threading draft to count ends assigned to each shaft individually.
Count ends per shaft from draftHeddle Capacity Check
Verify each shaft has enough heddles installed. Keep 5–10% spare heddles for pattern changes and repairs.
Available heddles ≥ Required + 10% spareUpdated: July 2026
Example Scenarios
Straight twill threading distributes 90 heddles per shaft. Standard 12-inch shaft with 200 heddles has ample capacity.
Satin draft may put 150 ends on shafts 1 and 5, 75 on others — count from draft, not equal division.
Single rigid heddle with 200 slots/holes handles 200 ends maximum. Double heddle setup for 3-4 shaft patterns requires two heddles.
FAQ
At minimum, one heddle per warp end on each shaft that end uses. For 400 ends on 4-shaft straight draw: 100 heddles per shaft.
Purchase additional heddles matching your loom brand and shaft height (regular vs long). Some weavers tie heddle bundles temporarily for sampling.
Rigid heddles combine heddle and reed function. 'Heddle count' equals slots plus holes (typically equal numbers). One rigid heddle = one shaft equivalent.
Mark each threading column in the draft and tally ends per shaft. Weaving software (Fiberworks, WeaveIt) calculates automatically from entered draft.
Heddles must match shaft height and wire gauge for your loom brand. Universal tie-on heddles exist but check compatibility before purchasing.
About Heddle Calculator
Running short of heddles mid-threading stops your project before weaving begins. Enter total warp ends, number of shafts, and threading pattern to calculate heddles required per shaft and verify your loom capacity.