Directional/Nap Fabric Yardage Calculator
Napped or one-way print fabric needs every piece facing the same direction — which usually means buying more.
Why nap changes the yardage
Non-directional fabric lets pattern pieces get flipped and rotated to nest tightly and minimize waste. Napped fabric (velvet, corduroy, fleece) and one-way prints or plaids can't be flipped without the direction, sheen, or design looking wrong in the finished garment — so every piece has to point the same way, which is a much less efficient layout.
Where this estimate comes from
Pattern envelopes that include a "with nap" yardage column typically list somewhere around 10–20% more fabric than the "without nap" column, though the exact amount depends heavily on how many pattern pieces there are and how they're shaped. This calculator applies that same range to give you a ballpark when only the without-nap number is available.
Always check the actual pattern chart first
If your pattern envelope lists a specific "with nap" yardage, use that number instead of this estimate — it accounts for that exact pattern's piece count and shapes far better than a general percentage can.