Commercial Real Estate CAM Pro-Rata Reconciliation Calculator
Work out a tenant’s pro-rata share percentage and monthly CAM obligation from rentable square feet — with the gross-up, management and admin fees, controllable expense cap and year-end true-up all shown line by line, plus a downloadable PDF.
Pro-rata share = tenant RSF ÷ the denominator your lease specifies. Total GLA and occupied GLA give very different answers, so read the clause before you trust a number. Estimates only, not legal or accounting advice.
| Category | Pool | Tenant Share | $ / RSF | Type |
|---|
Pool figures are after any gross-up. Tenant share is % of each line across 5,000 RSF. Controllable lines are the ones a cap and an audit clause reach.
How to use the CAM reconciliation calculator
Four steps turn a lease and an expense ledger into a defensible number — the tenant’s pro-rata share, the monthly CAM, and the year-end true-up — with the gross-up, fees, and controllable cap shown line by line and a downloadable PDF statement.
Enter the premises
Tenant RSF, total GLA, and the pro-rata denominator your lease names — total, occupied, or custom.
Build the expense pool
The annual common-area lines, each tagged controllable, variable, or fixed.
Set fees, gross-up & cap
Management and admin fees, the gross-up target, and any controllable cap against the prior year.
Read results & save a PDF
Share, monthly CAM, the true-up balance, a category schedule, and a downloadable statement.
How the CAM obligation is calculated
It starts from the pro-rata share, builds the recoverable pool with the gross-up and fees, applies the share, then nets out any cap and base-year credits and reconciles against what was billed. Here is the exact math.
Worked example — 5,000 RSF in a 100,000 GLA center, 85% occupied, grossed up to 95%
Pro-rata share: 5,000 ÷ 100,000 = 5.00%
Gross-up factor: 95% ÷ 85% ≈ 1.118 on variable lines
Recoverable pool: $653k grossed + $16.7k mgmt + $43.5k admin ≈ $713k
Tenant gross share: $713k × 5.00% ≈ $35,656 / yr
Monthly CAM: $35,656 ÷ 12 ≈ $2,971
≈ $2,971/mo. Against $33,000 of estimates billed ($2,750 × 12), about $2,656 is due at the year-end true-up.
CAM reconciliation charts
Handy lookups for the levers that move a CAM bill — pro-rata share by denominator, the gross-up factor by occupancy, typical fee and cap ranges, and what each lease type actually passes through. Confirm your own lease before you rely on any figure.
| Denominator | Basis | Share | Who carries vacancy |
|---|---|---|---|
| 100,000 sf | Total GLA | 5.00% | Landlord |
| 95,000 sf | Custom / stated | 5.26% | Negotiated |
| 90,000 sf | Occupied GLA (90%) | 5.56% | Tenants |
| 85,000 sf | Occupied GLA (85%) | 5.88% | Tenants |
| 80,000 sf | Occupied GLA (80%) | 6.25% | Tenants |
Share = tenant RSF ÷ denominator. The same tenant swings from 5.00% to 6.25% purely on which square-footage figure the lease names — a 25% difference in every line of the bill.
| Actual occupancy | Factor to 95% | A $1,000 variable line becomes |
|---|---|---|
| 95% or more | 1.000 | $1,000 |
| 90% | 1.056 | $1,056 |
| 85% | 1.118 | $1,118 |
| 80% | 1.188 | $1,188 |
| 70% | 1.357 | $1,357 |
Factor = target occupancy ÷ actual occupancy, applied only to variable, occupancy-driven lines (utilities, janitorial, security). Fixed lines like taxes and insurance are never grossed up.
| Item | Typical range | Notes |
|---|---|---|
| Management fee | 3%–5% of CAM | On the pool, usually excl. taxes & insurance |
| Administrative fee | 10%–15% | Sometimes charged instead of a mgmt fee |
| Gross-up target | 90%–100% | 95% is the market standard |
| Controllable cap | 3%–7% / yr | Caps year-over-year controllable growth |
| Dispute / audit window | 30–90 days | Time to object after the statement |
Ranges are common U.S. practice, not rules — every lease is negotiated. Charging both a management and an administrative fee is frequent but often one or the other is negotiable.
| Lease type | Base-year stop | Tenant pays |
|---|---|---|
| Triple net (NNN) | $0 / RSF | Full pro-rata share of CAM, taxes & insurance |
| Base year / expense stop | e.g. $8.00 / RSF | Only the excess over the stop |
| Modified gross | Partial | Some categories passed through, others not |
| Full-service gross | Built into rent | Landlord absorbs; increases via escalations |
A base-year stop of $0/RSF is a triple-net lease — the tenant pays the whole share. Any positive stop means the landlord absorbs costs up to that level and the tenant pays only what’s above it.
RSF ÷ denominator
fees = pool
actual = true-up
The tenant’s number comes from three levers: the denominator that sets the share, the pool after gross-up and fees, and the true-up against what was already billed.
- Denominator — total GLA vs occupied GLA sets the tenant’s share of everything.
- Gross-up & fees — variable costs are restated to the target occupancy, then management and admin fees are added.
- Cap & true-up — a controllable cap limits growth, and the year-end true-up reconciles estimates to actual.
Everything the calculator works out
One set of lease terms and an expense ledger gives you a complete, defensible reconciliation — the share, the pool, the monthly, the credits, and the true-up.
Key figures every CAM bill depends on
Built for both sides of the CAM bill
From reviewing a landlord’s statement to building one and pricing a lease, the same calculator models the denominator, the gross-up, the fees, and the true-up.
Checking a landlord’s year-end CAM statement before cutting the check, and wanting to know if the true-up is fair.
- Confirm the denominator in the lease
- Recompute the share and the pool
- Flag double fees or a swept fee base
Building the reconciliation, applying the gross-up and cap, and setting next year’s monthly estimate.
- Gross up variable lines to target
- Apply fees and the controllable cap
- Issue a clear PDF statement per tenant
Modeling the CAM exposure of a deal before signing, and testing how the denominator, cap, and stop change the number.
- Compare total vs occupied GLA
- Test a cap and a base-year stop
- Price the all-in cost per RSF
7 tips for a defensible CAM reconciliation
Small habits keep a CAM bill honest and a true-up predictable, whether you’re paying it or preparing it.
CAM reconciliation FAQ
The pro-rata share, gross-up, fee, cap, and true-up questions people ask most before paying or preparing a CAM statement.
A CAM (common area maintenance) reconciliation is the year-end true-up between the estimated CAM a tenant paid monthly and their actual pro-rata share of the landlord’s operating costs. If estimates fell short, the tenant owes the difference; if they overpaid, they get a credit or refund.
The landlord totals the recoverable expenses, applies any gross-up and fees, multiplies by the tenant’s share, then subtracts what was billed. Most leases require this statement within a set number of months after year-end.
The pro-rata share is the tenant’s rentable square feet divided by a denominator the lease specifies — usually total gross leasable area (GLA) or occupied GLA. A 5,000 sq ft tenant in a 100,000 sq ft center is 5.00% on total GLA.
The denominator matters more than people expect. On occupied GLA at 85%, that same tenant’s share rises to about 5.88%, because the vacancy is spread across the tenants in place. Always confirm which measure your lease uses.
A gross-up restates variable, occupancy-driven expenses — like utilities, janitorial, and security — as if the building were nearly full, typically 95%. It keeps a half-empty property from under-recovering those costs and protects tenants from paying an unfair share as occupancy changes.
Only variable costs are grossed up; fixed items like taxes and insurance are not. The factor is target occupancy ÷ actual occupancy — at 85% actual and a 95% target, variable lines are multiplied by about 1.12.
Many leases add a management fee (often 3% to 5% of the CAM pool) and an administrative fee (often 10% to 15%) on top of the raw expenses. The management fee pays the property manager; the admin fee covers the overhead of running the recoveries.
Charging both is common but frequently negotiable — some leases allow one or the other. Fees are usually calculated excluding real estate taxes and insurance, so watch for a fee base that sweeps those lines in.
A controllable cap limits how much the controllable portion of CAM can rise year over year — commonly 3% to 7%. Controllable expenses are those the landlord can manage, like landscaping and repairs; taxes, insurance, and utilities are usually excluded as uncontrollable.
Caps can be cumulative, where unused room carries forward, or compounding, where each year builds on the last allowed amount. The wording changes how much you actually save, so confirm which type your lease uses.
In a base-year or expense-stop lease, the tenant pays only the CAM above a set amount per rentable square foot, rather than the full share. A base year fixes that stop at the first year’s actual expenses; an expense stop states a dollar figure.
A stop of $0 per RSF is effectively triple-net — the tenant pays the entire pro-rata share. Any positive stop means the landlord absorbs costs up to that level and the tenant pays only the excess.
A true-up bill means your actual pro-rata share came in higher than the monthly estimates you were billed. Costs may have risen, occupancy may have changed the gross-up, or the estimate was never reset after the last reconciliation.
A large true-up relative to what was billed is a flag that the monthly figure is stale. Ask the landlord to reset next year’s estimate to the new actual so you aren’t surprised again.
Usually yes. Most commercial leases give the tenant a window — often 30 to 90 days after the statement — to review, request backup, and object. Many leases also include an audit right that lets you inspect the landlord’s books.
Ask for the general ledger detail, not just category summaries, and check the denominator, gross-up, fees, and any capital items expensed in one year. Note the deadline the day the statement arrives, since the right to dispute typically expires.
General Estimating Notice: This calculator estimates a tenant’s pro-rata share, CAM obligation, and year-end true-up from the square footage, expense pool, fees, gross-up, cap, and lease terms you enter, using typical U.S. market figures. Actual recoveries depend entirely on the specific lease language, the measurement standard, exclusions, and how expenses are classified and amortized. It is not legal, accounting, or financial advice. Always read the lease and have a qualified attorney or accountant review any reconciliation before you rely on it. For planning purposes only.