About DrapeRight

DrapeRight is a free tool for working out how much curtain fabric to buy, built to get the parts other calculators fudge: the pattern repeat and the unit system.

Why we built it

Search for a curtain fabric calculator and you find plenty of them. Most are tucked at the bottom of a fabric retailer's site, set up for their own bolt widths, and many only work in one unit system. Worse, a lot of them quietly skip the pattern repeat or get the half-drop case wrong, which is exactly the part that wastes the most fabric. People order, cut, and find the widths do not match or the cloth runs short.

So we built one tool that does the whole job properly. It works in inches and yards or in centimetres and metres, covers every common heading with its correct fullness, and handles both straight and half-drop pattern repeats the way a workroom actually cuts them.

How the numbers are worked out

The estimates follow standard workroom drapery formulas. The number of widths is the track width times the heading fullness, divided by the usable fabric width, rounded up. Each cut length is the finished drop plus the header turn and the bottom hem, rounded up to a whole pattern repeat where the fabric has one. A half-drop repeat adds a single extra repeat to the order. These are the same methods published by fabric houses and workroom guides such as fabricforhome.com, janeclayton.com, and sew-helpful.com, made consistent and put behind one interface.

The cut list

The thing we are proudest of is the cut list PDF. It lists every drop to cut and its exact length, with the repeat and hems already added, plus the total fabric and the method note. You can hand it to a shop or a workroom and cut straight from it. It is built in your browser from your numbers, so nothing you type leaves your device.

What we do not do

We do not sell fabric, take an account, or send your measurements to a server. The calculator and the PDF run in your browser. We would rather be the free, honest tool you come back to than a storefront with a calculator buried at the bottom. Always buy a little extra and check your fabric width before you cut, because cloth is cut by hand and faults happen.

Have a question or a fix to suggest? Send us a note.