Define the complete cut piece
Begin with the finished shape, then add seam or hem allowance and any spacing needed between cuts. Use the real circle, ellipse, triangle or hexagon—not just its stated area.
- Confirm whether pattern dimensions already include allowances.
- Count mirrored, paired and duplicate pieces.
- Use the largest dimensions when pieces are irregular.
Enter usable fabric width
A piece that is slightly too wide forces a different orientation, another row or a panel method. Exclude selvedges and any unusable edge from the width.
- Do not assume every nominal 150 cm cloth provides 150 cm of clean cutting space.
- Verify width before purchase when the fit is close.
- Keep every generated piece inside the shown boundary.
Choose a layout the fabric permits
Staggered circles and ovals, alternating triangles and tessellated hexagons can reduce geometric waste. Directional prints, nap and motif placement can remove some of that freedom.
- Optimised rows are not full industrial nesting.
- One-way designs keep a consistent top.
- Repeats and plaid matching may require extra length.
Add risk allowance, then round for the shop
Buying allowance covers practical uncertainty such as shrinkage, squaring and minor defects. Retailer increment is the amount the shop will actually cut—for example 0.1 m or 1/8 yd.
- Apply allowance before retailer rounding.
- Never round the geometric engine at every intermediate step.
- Use the calculator’s recommended purchase as the shopping number and keep the minimum as the planning reference.