Let sheet size be \(S_w \times S_h\), unprintable margin per edge \(m\), bleed per edge \(b\), kerf (gap) between pieces \(k\). Let unfolded card piece be \(C_w \times C_h\). For a single fold with side fold: \(C_w = 2\,W\), \(C_h = H\). For top fold: \(C_w = W\), \(C_h = 2\,H\). For flat panels: \(C_w = W\), \(C_h = H\). Effective sheet area: \(S'_w = S_w - 2m\), \(S'_h = S_h - 2m\). Place rectangles with gutters \(g = k + 2b\) in a grid. Rows (no rotation): \(r = \left\lfloor \dfrac{S'_h + k}{C_h + g} \right\rfloor\), columns: \(c = \left\lfloor \dfrac{S'_w + k}{C_w + g} \right\rfloor\). If rotation allowed, compute \(r^*, c^*\) swapping \(C_w, C_h\); choose the max \(N = \max(rc, r^*c^*)\). Waste: \(\text{waste} = 1 - \dfrac{N\,(C_w\,C_h + g\,C_w + g\,C_h + b^2)}{S'_w S'_h}\) (approx. area‑based with gutters & bleed).