Sewing, Knitting & Craft Project Calculation Guide

📚 Overview

Most craft projects fail on quantities, not skill. Buying too little fabric or yarn can stop a project halfway, and a dye lot that no longer matches cannot be fixed. A few simple formulas turn project dimensions into yardage, stitch counts, and material weights, so you can buy the right amount the first time and waste less.

📐 Fabric Yardage & Gauge-Based Stitch Count

Fabric widths = total finished width / fabric width, rounded up. Cut length = finished length + hem and heading allowances. For knitting, gauge is stitches per inch measured on a washed, blocked swatch.

🔢 Worked Example

Scenario: Making double-fullness curtains for a 60 inch wide window with an 84 inch drop in 54 inch wide fabric, then casting on a 40 inch wide blanket from a 20 stitch by 4 inch swatch.

• Window: 60 in wide, 84 in drop
• Fullness: 2x, hem and heading allowance: 12 in
• Fabric width: 54 in
• Swatch: 20 stitches over 4 in

1. Total width = 60 × 2 = 120 in, so widths = 120 / 54 = 2.22, rounded up to 3
2. Cut length = 84 + 12 = 96 in
3. Yardage = 3 × 96 / 36 = 8 yards
4. Stitches per inch = 20 / 4 = 5, so cast-on = 40 × 5 = 200 stitches

💡 Pro Tips

• Wash, dry, and block fabric and swatches the way you will care for the finished item, since shrinkage can change quantities by 5 percent or more.
• Buy all yarn for a project in one go from the same dye lot, because colours can differ slightly between lots.
• Add a safety margin of 10 percent for fabric and yarn, and more for patterned fabric that needs matching.
• Round fabric widths up, never down. A partial width still has to be bought as a whole width.

🧮 Sewing & Crafts Calculators (15)

Put the formulas above into practice with these free tools:

❓ Frequently Asked Questions