How to estimate good dies per wafer

"How many chips per wafer?" is one of the first economic questions in chip design. Two Semitree tools get you a quick estimate.

Step 1 — gross dies per wafer

Open the Die-per-wafer calculator and enter the wafer diameter and die size. It uses the de Vries approximation, which subtracts an edge term for partial dies lost at the wafer's rim.

Step 2 — apply yield

Not every die works. Open the Wafer-yield calculator, enter your defect density and die area, and pick a model (Poisson or Murphy). Multiply gross dies by the yield fraction to estimate good dies.

1. Gross dies = die-per-wafer estimate.
2. Yield = wafer-yield calculator output.
3. Good dies ≈ gross dies × yield.