To calculate economic occupancy, divide the rent you actually collected during a period by the gross potential rent for that same period, then multiply by 100. A 200-unit property with $300,000 in monthly gross potential rent that collects $276,000 has an economic occupancy of 92%. The gap between those two numbers is where vacancies, below-market leases, concessions, and unpaid rent show up.
The rest of the work is figuring out what belongs in each side of that fraction.
Step 1: Calculate Gross Potential Rent
Gross potential rent (GPR) is the theoretical maximum income your property could produce if every unit were leased at current market rates for the entire period. This is the denominator, so getting it right matters.
Multiply the market rental rate for each unit type by the number of units of that type, then add them together. Fifty one-bedrooms at $1,400 and fifty two-bedrooms at $1,800 give you a monthly GPR of $160,000. Use market rates, not the rates your current tenants are paying. The point is to measure the property’s full earning capacity, not its current contract obligations.
Market rates come from recent comparable leases in the area. Property management software usually pulls this from lease comps, and listing data for similar floor plans nearby works as a check. Use the same methodology each month so your trend line reflects real changes rather than measurement noise.
Step 2: Add Up the Revenue Deductions
Once GPR is set, catalog every dollar of income that didn’t materialize. Miss a category and the resulting percentage will overstate performance.
Vacancy Loss
Empty units produce zero income. Multiply the market rent for each vacant unit by the days or months it sat empty during the period. A unit vacant for half a month at $1,800 market rent is $900 in vacancy loss.
Some vacancy is structural. Units need to be turned between tenants, and that takes time under the best circumstances. The controllable portion is the stretch between when a unit is rent-ready and when a new tenant moves in.
Loss to Lease
Loss to lease is the gap between what current tenants pay under their signed leases and what those same units would rent for at today’s market rate. A tenant who signed a year ago at $1,400 in a unit now leasing at $1,550 produces $150 per month in loss to lease. Roll that across every below-market lease in the building.
Every unit generating loss to lease is occupied and producing income, which is why physical occupancy misses it entirely. Some loss to lease is inevitable because rents move between renewals, but a large gap signals that renewals haven’t kept pace with the market or that lease terms are too long.
Concessions
Concessions are financial incentives offered to attract or retain tenants: a free month, a reduced first-90-days rate, a waived application fee. The unit is occupied and technically generating income, but the concession reduces total revenue below what GPR assumed.
Spread recurring concessions across the lease term rather than booking them entirely in the month granted. A one-month-free concession on a 12-month lease reduces each month’s collected rent by one-twelfth of the monthly rate. That gives a cleaner month-to-month picture.
Bad Debt
Bad debt is rent that was billed, sits on the rent roll as owed, and was never collected. The unit is occupied, the lease is in place, and the tenant simply isn’t paying. Eventually the balance gets written off after eviction or collections.
Bad debt is lumpy rather than steady. One or two problem tenants can swing economic occupancy by a full percentage point in a given month. Track it separately from vacancy, because vacancy is a leasing problem and bad debt is a screening and collections problem.
Non-Revenue Units
Model units, employee-occupied apartments, and units taken offline for renovation reduce income without being vacant in the traditional sense. A model apartment that could rent for $1,600 per month costs the property $19,200 per year in forgone revenue. Staff units where employees live rent-free have the same effect.
Include these in your deductions. Some operators prefer to exclude non-revenue units from GPR entirely rather than count them as a deduction. Either approach works if you’re consistent, but including them in GPR and then deducting them produces a more conservative number.
Step 3: Run the Formula
Subtract total deductions from GPR to get actual collected revenue, then divide by GPR and multiply by 100. Worked out on a 200-unit property:
- GPR: 200 units at an average market rent of $1,500 = $300,000 per month
- Vacancy loss: 10 empty units = $15,000
- Loss to lease: $4,000 across 40 below-market leases
- Concessions: $2,000 in move-in specials amortized across the month
- Bad debt: $3,000 in unpaid rent from delinquent tenants
- Total deductions: $24,000
- Actual collected revenue: $300,000 − $24,000 = $276,000
- Economic occupancy: ($276,000 ÷ $300,000) × 100 = 92.0%
The property captured 92 cents of every dollar it could have earned. The remaining 8% leaked out through vacancies, pricing gaps, giveaways, and non-paying tenants.
Physical Occupancy Is Not the Same Number
Physical occupancy counts bodies in units. If 95 out of 100 apartments have tenants, physical occupancy is 95%. That number hides whether those tenants are paying, whether they’re paying market rates, and whether you gave half of them a free month to sign. A building can be physically full and still bleed money.
Economic occupancy closes that blind spot by tracking dollars instead of headcounts. In the worked example above, physical occupancy sits at 95% (190 of 200 occupied) while economic occupancy is 92%. Two properties with identical physical occupancy can produce very different economic occupancy figures, and the difference usually points to management quality and pricing strategy.
Always look at both. If someone offers only a physical occupancy figure, the economic number is the one you actually want.
Where to Pull the Numbers
The calculation depends on clean data. The rent roll lists every unit, its lease status, the contract rent, and any outstanding balances. Most property management platforms generate it automatically. Cross-reference the rent roll against individual lease agreements to confirm the rates match, especially after renewals, where manual entry errors are common.
The profit and loss statement shows actual cash collected during the period. That’s where you’ll find real numbers for concessions granted, bad debt written off, and other income adjustments. Pull both reports for the same period and reconcile any discrepancies before running the formula. A one-month timing difference between the rent roll snapshot and the P&L can shift economic occupancy by a percentage point or two.
What the Result Means
A well-run multifamily property generally targets economic occupancy of 90% or higher. Below 90%, something meaningful is dragging on revenue, and it’s worth investigating which deduction category is doing the most damage.
The gap between physical and economic occupancy tells its own story. A spread of two to three percentage points is normal and reflects the unavoidable friction of lease turnover and minor concessions. A gap of five or more points signals a deeper issue, often heavy concessions used to mask weak demand or a chronic bad-debt problem that better tenant screening could address.
A single month’s figure is useful. Averaging monthly economic occupancy across twelve months is more useful, since one-time events like a large bad-debt write-off or a seasonal vacancy spike can distort any single snapshot. Keep the GPR methodology consistent from month to month, and don’t retroactively adjust prior months when market rents change. The goal is to see how revenue capture moved over time, not to rewrite history with updated assumptions.