PCM Sample Cost Calculator

Example input and output table

Example totals are illustrative. Your project may require additional fees or regional tax rules.

Formula used

• Direct sample cost = Sample Quantity × Base Cost per Sample
• Direct subtotal = Direct sample cost + (Lab prep + Shipping + On-site + PPE + Documentation)
• Rush fee = Direct subtotal × Rush %
• Overhead = (Direct subtotal + Rush fee) × Overhead %
• Contingency = (Direct subtotal + Rush + Overhead) × Contingency %
• Pre-tax total = (Direct subtotal + Rush + Overhead + Contingency) − Discount
• Tax = Pre-tax total × Tax %
• Grand total = Pre-tax total + Tax
• Cost per sample = Grand total ÷ Sample Quantity

How to use this calculator

1. Enter the number of PCM samples and your base cost per sample.
2. Add fixed fees such as lab preparation, shipping, and collection costs.
3. Apply percentage add-ons for rush processing, overhead, and contingency.
4. Enter any discount or credit, then specify your tax rate if applicable.
5. Click Calculate to display totals above the form.
6. Use Download CSV or Download PDF to save results.

Cost drivers in PCM sampling budgets

PCM sample cost control starts with separating unit testing cost from fixed fees. In many projects, base per-sample pricing represents 60–85% of the direct subtotal. Fixed items like shipping, documentation, and PPE can dominate when quantities are low. Tracking these components helps procurement compare vendors and avoid under-quoting early-stage surveys.

Quantity planning and coverage assumptions

Sample quantity should align with grid density, materials, and phasing. A practical approach is to model three scenarios: minimum coverage, expected coverage, and worst-case coverage. For example, increasing quantity from 10 to 18 samples can raise direct sample cost by 80%, but fixed fees may stay nearly constant. This calculator highlights the non-linear effect of fixed charges on cost per sample.

Fees that commonly change the bid total

Lab preparation fees and shipping often vary by turnaround and hazardous handling requirements. On-site collection cost can be driven by access controls, travel time, and safety coordination. Documentation and custody fees are frequently overlooked, yet they are essential for defensible reporting. Enter each fee separately to maintain auditability and support change-order discussions.

Managing rush, overhead, and contingency

Rush percentage is applied to the direct subtotal, which means it scales with both unit and fixed costs. Overhead and contingency then compound on top of rush, reflecting real-world project risk. Typical ranges are 0–25% for rush, 5–20% for overhead, and 3–15% for contingency, depending on schedule pressure and site uncertainty.

Using outputs for approvals and reporting

Use the grand total for approvals and the cost per sample for benchmarking across sites. If tax applies, include it after discounts to match standard invoicing practice. Export CSV for estimating sheets and PDF for attachments in submittals or internal approvals. Keeping scenario outputs on file improves transparency and speeds review cycles.

What does PCM mean in this context?

PCM refers to phase change material sampling used in construction quality checks or material verification. The calculator estimates budgeting costs for collecting, preparing, shipping, and processing those samples.

Should overhead be applied before or after contingency?

This tool applies overhead first, then contingency on the subtotal including overhead. That mirrors many estimating practices where contingency reflects risk on the full managed cost, not only direct expenses.

How is the rush fee calculated?

Rush fee is calculated as a percentage of the direct subtotal (unit sample cost plus all fixed fees). If you want rush on lab work only, enter lab-related fees separately and adjust accordingly.

What if discount is larger than the subtotal?

The calculator prevents negative totals by flooring the pre-tax total at zero. If credits exceed charges, confirm the vendor’s credit policy and whether it should carry to a future invoice.

Why is tax applied after discount?

Many invoicing systems calculate tax on the net amount after discounts. If your jurisdiction taxes pre-discount totals, set discount to zero and represent credits as separate accounting entries.

Can I use this for multiple sites?

Yes. Run separate calculations per site or phase so fixed fees and quantities stay realistic. Export each run as CSV or PDF and attach the files to your estimating package.