Sewing calculators

What these tools solve

The fabric yardage calculator turns finished width and length, bolt width, optional pattern repeat, and waste into a shopping length in yards or meters. Use it for garments, curtains, upholstery covers, and tablecloths when you need a planning figure before you visit the store. The seam allowance calculator converts finished measurements to cut sizes, grades a measurement between sizes, or adds wearing ease. Neither tool replaces a full commercial pattern’s yardage chart; both keep arithmetic local in your browser.

How to measure before you buy

• Measure the finished width and length you want (window opening for curtains, table top for cloths, body or pattern piece for garments).
• Note the usable fabric width on the bolt (often about 44/45″ or 54/60″ for apparel and home décor—confirm in the store).
• Add hems, headers, and seam allowances before cutting; the tools’ waste and seam fields exist for that buffer.
• If the print has a vertical repeat, enter it so panel lengths can round up to a matching motif.

Worked example: curtain panels

Window 48″ wide × 84″ drop, 2× fullness, 54″-wide fabric, 10% waste. Total width needed = 48 × 2 = 96″ → ceil(96 ÷ 54) = 2 panels. Each panel length ≈ 84 + 10″ hem/header = 94″. Two panels = 188″; ×1.10 waste ≈ 206.8″ ÷ 36 ≈ 5.74–5.9 yards depending on rounding—matches the takeaway above when you run the same inputs in the fabric yardage calculator.

Worked example: finished to cut size

A pocket that should finish 5″ wide with ⅝″ seam allowance on both sides needs a cut width of 5 + 2 × 0.625 = 6.25″. Use the seam allowance calculator when you are drafting or altering rather than following a printed cutting layout.

Common mistakes

• Shopping from finished size only and forgetting hem, header, or seam allowance.
• Ignoring directional prints or naps that force extra length for matching.
• Treating garment “coverage factor” estimates as a substitute for a graded pattern chart—always prefer the pattern when you have one.
• Assuming every bolt is 45″ usable; selvages and printing can shrink the usable width.

Guides and related hubs

When you want yardage explained in words, read how many yards of fabric you need. Quilters often need binding, backing, and the quilting hub next. Knitters and crocheters shopping yarn instead of woven fabric should start at the knitting & crochet hub. Charts for mattress and quilt top sizes live under quilt & mattress sizes.

Planning assumptions for fabric tools (fullness defaults, hem add-ons, waste) are documented as heuristics on Methodology. Prefer a published pattern’s tested yardage when it conflicts with a calculator estimate.