Free bobbin lace calculators
Useful geometry and sample-based planning tools for prickings, repeated strips and thread preparation.
Bobbin lace varies by lace type, stitch, thread and pricking, so pattern-specific choices stay in your hands instead of being replaced by invented universal ratios.
Every calculator is free. No account or membership. Voluntary support is welcome, never required.
Prepare your bobbins with confidence.
What would you like to work out?
Scale a pricking or pattern
Calculate a proportional enlargement or reduction and matching printer scale.
Open Pattern Scale Calculator →Plan repeated lace
See how many complete repeats fit a target section and how many reach or exceed it.
Open Repeat Calculator →Estimate thread from a sample
Scale measured total thread use from a representative sample and add your own reserve.
Open Thread Estimator →Tile a pattern for printing
Work out how many printable sheets are needed from the pattern size, printable sheet area and overlaps you choose.
Open Pattern Tiling Calculator →Prepare bobbins and winding thread
Calculate bobbin count and total preparation thread from your pair count and a per-bobbin length you supply.
Open Bobbin Winding Calculator →Pattern first
The Lace Guild notes that a pricking suited to one thread thickness may need enlarging for thicker thread or reducing for thinner thread. The amount is pattern-specific, so the scale tool calculates the geometric change you request rather than choosing thread for you.
Worker and passive bobbins
Thread use can differ between bobbins. The estimator therefore works from total measured sample use and labels any per-bobbin figure as an average only.
Bobbin lace calculator questions
Does the scale calculator choose thread for me?
No. It calculates geometry only.
Why is the thread estimate sample-based?
Different structures, worker paths and tensions consume different amounts.
Are these tools free?
Yes. Pattern Calculator is free to use and is intended to remain free.
Further reading: The Lace Guild.