About Quilt Backing Calculator

Who runs this site

I'm Ian Welkins. I build calculator websites for crafts where a wrong number costs real material — and quilting is exactly that kind of craft. A yardage figure that is half a yard short doesn't produce a slightly worse quilt; it produces a second trip to the fabric shop and, if the bolt has sold out, a different quilt than the one you planned.

The site started with the backing question — how much fabric for the back of this quilt? — because it is the calculation quilters make most and guess worst. The other tools followed the same logic: each one answers a single fabric question, shows its method openly, and checks its arithmetic against published sources.

How the numbers are sourced

No formula on this site was invented at a keyboard. The diagonal backing calculator implements John Flynn's published formula, worked example included, and the page reproduces his own numbers so you can verify it. The binding calculator follows Missouri Star Quilt Co.'s perimeter-plus-allowance method. Batting recommendations use the standard pre-cut package sizes sold by The Warm Company and others. Where a calculator makes a modeling choice — the straight-cut border model, the sashing construction — the page says so plainly and tells you how to adapt the result.

Every worked example on the site is generated by the same code that runs the calculators, and the code is tested against hand-computed cases. When a quilter reports a discrepancy, it is investigated and, if the site is wrong, corrected publicly — the editorial policy describes how, and the error report form is always open.

What the site is not

It is not a shop: nothing is sold here, and no calculator result is influenced by anyone's fabric inventory. It is not a pattern library or a tutorial channel — it does one job, the arithmetic, and links you onward for the rest. And it is not finished: quilting has more fabric questions than any one site launch covers, and the toolbox grows as readers ask. Start with the backing calculator — it is the tool the site is named for, and still the one most quilters need first.