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I Built a Free Fabric Yardage Calculator — Here is Why Even Experienced Sewers Get This Wrong

Why I Built This

I have been sewing for years and I still messed up yardage calculations more times than I want to admit. Buying too much is wasteful. Buying too little means unmatched dye lots — and that is a disaster for any project.

So I built YardageCalc — a free fabric yardage calculator that updates results as you type. No button clicking, no page reloads.

The One Mistake Almost Everyone Makes

It is not forgetting seam allowance (though that is common too). It is not flooring your pieces-per-width. Here is what I mean:

54" fabric ÷ 21" piece = 2.57

Most people round that to 3. But you cannot fit 2.57 pieces across 54" — you can only fit 2. The 0.57 is wasted space. If you round up, you overbuy by 50%.

The correct calculation: floor(54 ÷ 21) = 2 pieces per width.

The 5-Step Formula

  1. Cut size = project dimension + (seam allowance × 2)
  2. Pieces per width = floor(fabric width ÷ cut piece width)
  3. Rows needed = ceil(total pieces ÷ pieces per width)
  4. Total inches = rows × cut length
  5. Yards = (total ÷ 36) × (1 + waste%)

Common Yardage References

Project 54" Fabric
Throw pillow 18×18" ½ yard
Curtain panel 84" 2½ yards
Knee-length dress 2-2½ yards
3-seat sofa upholstery 14-16 yards

I also made a free cheat sheet with all the common yardages — save it to your phone for fabric shopping trips.

The calculator handles metric, cost estimation, pattern repeats, width comparison, and even emails your results. Try it: https://yardage-calc.com/

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