Estimate Your CAM Reconciliation Amount
At the end of each lease year, landlords reconcile estimated CAM payments against actual expenses. If actual expenses exceed estimates, tenants pay a "true-up." If estimates exceeded actuals, tenants receive a credit. This calculator walks through the reconciliation math.
By Angel Campa, Founder · Updated March 2026
The Formula
CAM True-Up = (Actual CAM Expenses × Tenant Pro-Rata Share) − Monthly CAM Paid
A positive result means you owe additional payment. A negative result means you are owed a credit. Gross-up provisions may adjust actual expenses upward if occupancy was below the contractual threshold (often 90–95%).
Worked Example
Example Inputs
| Total Building CAM Expenses (Actual) | $240,000/year |
| Total Rentable Building Area | 50,000 sq ft |
| Tenant Leased Area | 5,000 sq ft |
| Tenant Pro-Rata Share | 10.00% (5,000 ÷ 50,000) |
| Monthly CAM Estimate Paid | $1,900/month ($22,800/year) |
| Building Occupancy During Year | 85% |
Result
Tenant owes $1,200 (base case); $4,024 if lease has 95% gross-up provision
Step-by-Step Breakdown
| Line Item | Value |
|---|---|
| Tenant's Share of Actual CAM | $24,000/year |
| CAM Estimated Already Paid | $22,800/year |
| Base True-Up (no gross-up) | $1,200 owed |
| Grossed-Up CAM (95% threshold) | $268,235/year |
| Tenant's Share (Grossed-Up) | $26,824/year |
| True-Up with Gross-Up | $4,024 owed |
Frequently Asked Questions
What is a CAM reconciliation?
CAM reconciliation is the annual process by which landlords compare actual common area maintenance (CAM) expenses against the estimated payments tenants made throughout the year. If actual expenses exceeded estimates, the tenant pays a true-up. If estimates exceeded actuals, the tenant receives a credit or carryforward.
What is a gross-up provision in a lease?
A gross-up provision allows the landlord to adjust CAM expenses as if the building were at full occupancy (typically 90–95%) when calculating tenant expense shares. This prevents tenants from benefiting from low-occupancy years when variable expenses like utilities and cleaning are artificially low.
How do I know if my CAM reconciliation is accurate?
Tenants with audit rights can request the landlord's supporting expense documentation within the window specified in the lease (typically 30–90 days after receiving the reconciliation). Common errors include inclusion of excluded expense categories, incorrect pro-rata share calculations, and capital expenditure misclassification as operating expenses.
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