An eight-layer PCB unit price cannot be inferred from layer count alone. Board area, usable panel layout, quantity, process steps, testing and commercial terms all matter. A transparent planning model helps you understand these relationships without presenting invented rates as a supplier quotation.
Define the panel before calculating the unit price
Consider a 100 × 80 mm board on a 457 × 610 mm manufacturing panel, with a 15 mm rail on every edge and 3 mm spacing between boards. These dimensions are illustrative. After subtracting rails, the usable rectangle is 427 × 580 mm.
For an axis-aligned grid, the fit count along one axis is floor((usable dimension + spacing) / (board dimension + spacing)). The added spacing in the numerator prevents charging a gap beyond the last board. Compare both uniform orientations; this simple model does not attempt mixed-orientation nesting.
| Orientation | Along width | Along height | Boards / panel |
|---|---|---|---|
| 100 × 80 mm | floor(430 / 103) = 4 | floor(583 / 83) = 7 | 28 |
| 80 × 100 mm | floor(430 / 83) = 5 | floor(583 / 103) = 5 | 25 |
Apply yield and whole-panel rounding
At 28 boards per panel and an assumed 95% yield, the expected acceptable quantity per panel is 26.6. For 100 delivered boards, the planning count is ceil(100 / 26.6) = 4 panels. This is an expectation, not a guarantee that four physical panels will produce exactly the required acceptable quantity.
Board-area utilization is 28 × 100 × 80 / (457 × 610) = approximately 80.35% of the full panel area. Utilization is different from production yield: the first measures geometric material use; the second is an assumed fraction of acceptable boards. Do not substitute one percentage for the other.
Make every rate visible
Use an illustrative material-set rate of $120/m², surface finish at $35/m², processing at $65/panel, electrical test at $0.50/delivered board and engineering/setup at $180/order. Panel area is 0.27877 m². The material rate represents the entire eight-layer material set, so multiplying it by eight again would double-count that assumption.
| Line item | Calculation | Illustrative budget |
|---|---|---|
| Material | 4 × 0.27877 × $120 | $133.81 |
| Finish | 4 × 0.27877 × $35 | $39.03 |
| Panel processing | 4 × $65 | $260.00 |
| Electrical test | 100 × $0.50 | $50.00 |
| Engineering/setup | Once per order | $180.00 |
| Total / unit | Approximately $662.84 / 100 | $6.63 per board |
These figures teach the model; they are not current market prices, a minimum order commitment or an offer from 8layerPCB.com. Freight, tax, commercial margin and any process not covered by the entered panel rate are excluded.
Why quantity breaks are not perfectly smooth
Increasing quantity spreads setup costs over more boards, but panel rounding creates steps. A small quantity increase can trigger one additional full panel. The calculator compares several quantities using the same dimensions, rates and yield assumption so you can see this behavior directly.
A real supplier may use pooling, different panel sizes, different pricing tiers or a different yield model. Consequently, the simulated curve should guide questions rather than be treated as a prediction of the supplier’s price list. Ask which panel and array assumptions are included in the actual quotation.
Compare quotations on the same basis
- Use the same released file revision and delivered board count.
- Match material grade, copper, finish and via architecture.
- Identify tooling/setup charges and whether they recur on repeat orders.
- Match impedance testing, electrical testing, inspection reports and acceptance criteria.
- Separate dispatch lead time from shipping transit and arrival date.
- Compare freight, tax, currency and payment terms before choosing the lowest unit price.
Use the model to test a decision
Open the manufacturing cost calculator. Change the outline by a few millimeters or increase the rail allowance, and check whether boards per panel falls. Then replace the illustrative rates with a consistent supplier-provided budget. Retain the panel dimensions and all rates alongside the result so another person can reproduce it.
For a firm project price, submit your controlled files and requirements through the RFQ page. Manufacturing cost context: Würth Elektronik: how PCB layout influences manufacturing costs. The numerical example and arithmetic above are original illustrative calculations.