Thread Length Converter & Spool Estimator

Thread weight is measured in wt (weight): 40wt is standard embroidery, 30wt is heavier, 60wt is finer. Higher numbers mean thinner thread. Weight affects coverage, stitch density, and the look of the finished design.

1 metre = 1.094 yards. 1 yard = 0.914 metres. Many US patterns and thread brands use yards; UK and European brands use metres. This calculator converts between them automatically.

Mini spools: 200-500m. Standard spools: 1,000m. King spools: 5,000m. Cones: 5,000-10,000m. For occasional use, standard spools are fine. For production work, king spools or cones are more economical.

Yes. Heavier threads (30wt, 12wt) take up more space on the same physical spool, so it holds fewer metres than a finer 40wt or 60wt thread. The exact put-up varies by brand — always check the metres or yards printed on the reel rather than assuming, as Madeira, Isacord and Aurifil all wind differently. This calculator converts the length you actually have; it does not estimate weight-to-weight equivalence.