How to Calculate Cost-Per-Unit for CAD/CAM Milling
Most dental labs know what they charge per crown. Fewer know precisely what each crown actually costs to produce. Without an accurate cost-per-unit figure, you can't confidently set pricing, evaluate supplier changes, justify equipment investments, or compare your in-house costs against outsourcing options. Here's how to calculate it correctly.
The Five Cost Categories
1. Material Cost
The most direct cost. For a zirconia crown:
- Disc cost ÷ units per disc = material cost per unit
A 98.5mm x 18mm disc at $40 that yields 10 full-contour units = $4.00 material cost per crown. Track actual yield; nesting inefficiency or cracking reduces effective yield. Losses that come from pre-milling bur failures or material defects belong in this cost.
2. Tooling Cost (Burs)
- Bur set cost ÷ lifecycle units = bur cost per unit
If your roughing bur costs $18 and lasts 50 units, and your finishing bur costs $22 and lasts 40 units: ($18/50) + ($22/40) = $0.36 + $0.55 = $0.91 per unit in bur cost. Include all burs used in the job — pre-milling, step, finishing.
This calculation requires knowing your actual lifecycle count. If you're not tracking bur counts, you're estimating this number, which means your cost figure is unreliable.
3. Equipment Amortization
Capital equipment has a useful life. Spread that cost across the units produced:
- Mill cost ÷ useful life in units = amortization per unit
A $35,000 mill expected to produce 100,000 units over its life = $0.35 per unit in equipment amortization. Also include sintering furnace, scanner, and CAD/CAM software amortization in the calculation for a complete picture. Factor in expected service costs over the equipment lifetime.
4. Labor
Labor is often underestimated because it's allocated across multiple tasks:
- CAD design time per unit (often 10–20 minutes for a standard crown)
- Milling setup and monitoring time
- Post-milling handling: depinning, cleaning, coloring, loading the sintering furnace
- Quality inspection
Total minutes per unit × technician hourly rate ÷ 60 = labor cost per unit. For a 30-minute total touch time at $30/hour: $15 per unit in labor.
5. Overhead
Fixed overhead allocated to the CAD/CAM workflow: facility space, utilities (sintering furnaces draw significant power), compressed air, IT, and administrative burden.
Simplified approach: total monthly overhead attributable to CAD/CAM ÷ monthly unit output = overhead per unit.
Sample Cost Roll-Up
| Cost Category | Example Per Unit |
|---|---|
| Zirconia disc material | $4.00 |
| Tooling (burs) | $0.91 |
| Equipment amortization | $0.60 |
| Labor (30 min @ $30/hr) | $15.00 |
| Overhead allocation | $3.00 |
| Total cost per unit | $23.51 |
Using This Number
With an accurate cost-per-unit, you can:
- Set pricing with confidence (cost + target margin = floor price)
- Evaluate material supplier changes (does a cheaper disc actually save money after yield differences?)
- Justify equipment upgrades (does a faster mill reduce labor cost enough to offset the investment?)
- Compare in-house vs outsourcing economics on specific case types
Recalculate this number whenever a significant variable changes: supplier pricing shift, new material, equipment replacement, staffing change.