The easiest measurement in the world is the sail already on your boat. Bag it, send it, and our loft floor does the rest. But there's a catch worth understanding, and every one of our measurement forms says it out loud.
Before you put a tape on anything
Lay the sail flat, pull each edge taut without stretching it, and measure corner to corner: Lp the luff, Lw the leech, Ld the foot. Use the same marked point at each corner for both edges that meet there. Or don't do any of it — send us the sail and we'll measure it on a flat floor with proper tension, which is what we'd do anyway.
The coded measurements
| Code | What it is, and where the tape goes | Where |
|---|---|---|
| LpLuff | Tack to head, along the leading edge. | |
| LwLeech | Head to clew, along the trailing edge. | |
| LdFoot | Tack to clew, along the bottom. |
Why your old sail is “reference only”
Look closely at our headsail form and you'll see those three numbers sit under a heading that reads “Old sail measurements — reference only.” The spinnaker form is blunter: “Do not substitute specifications or an old sail.”
Here's why. Sailcloth stretches. A ten-year-old genoa is measurably bigger than the day it was cut, and it's bigger unevenly — most where the load was highest, along the luff and the leech. Copy those numbers faithfully and we'd build you a brand-new sail with a decade of someone else's stretch baked into it: too full, draft too far aft, hooking leech. A perfect replica of a worn-out sail.
So we use both, for different things. Your old sail tells us what you had — the cut, the hardware, the wear pattern, what actually failed. Your rig tells us what fits. We measure the sail on the floor, deduct for stretch on every edge, check it against the rig numbers, and send you the production dimensions to approve before anything is cut.
That's also why an instant estimate on this site is an estimate. In our forms' own words: “An estimate is not a binding production size until this review is complete.”
The rule that runs through every form we print
If you aren’t sure of a bearing, leave it blank and tell us. Our forms say it on every page, and it isn’t politeness — it’s arithmetic. A blank is a question we can answer with one phone call. A guess is indistinguishable from a measurement, so it survives all the way to the cutting floor and comes back as a sail that doesn’t fit. We would rather have four honest numbers and a note than five numbers where one is fiction.
The words on this page, explained
Or don’t measure anything at all
The easiest measurement is the sail you already own. Bag it, send it, and we’ll do all of this on a flat loft floor with proper tension — then send you the production dimensions to approve before we cut.