Formula
GPR = Σ (market rent per unit × 12)
The course's own definition: it cites no published source.
- Market rent
- What the space would command today per month, not necessarily what the current lease says.
How it works
GPR is a deliberately hypothetical number, and that is its purpose. By starting from a full-occupancy, market-rent ceiling, an operating statement makes every deduction below it explicit and measurable: how much is lost to vacancy, how much to concessions, how much to the gap between in-place and market rents. Starting instead from actual collections hides all of it in a single figure.
The most consequential judgment in building GPR is whether to use market rent or in-place rent. Underwriters generally build GPR at market and then show loss-to-lease as a separate deduction: the difference between what units would command and what existing leases actually charge. That line is where a value-add thesis lives: a property with $60,000 of annual loss-to-lease has $60,000 of income available simply by renewing at market as leases roll.
GPR also exposes the difference between a physically full building and a financially full one. A property at 100% occupancy where half the tenants signed two years ago at below-market rents produces far less than its GPR, with no vacancy at all. Comparing occupancy figures between properties tells you less than comparing each one's collections against its own GPR.
For commercial space the calculation runs on rentable square feet rather than units: market rent per square foot times rentable area, times twelve only when the rent is quoted per square foot per month. A rent quoted per square foot per year is already annual and is multiplied by the rentable area alone; multiplying it by twelve overstates GPR twelvefold. Where leases carry expense recoveries, those are recorded as other income rather than folded into GPR, so the rent line stays comparable across lease structures.
Worked example
A 40-unit apartment building: 24 one-bedroom units at a market rent of $1,400 and 16 two-bedroom units at $1,850. Existing leases average $75 per unit per month below market.
| Step | Calculation | Result |
|---|---|---|
| One-bedroom annual potential | 24 × $1,400 × 12 | $403,200 |
| Two-bedroom annual potential | 16 × $1,850 × 12 | $355,200 |
| Gross potential rent | $403,200 + $355,200 | $758,400 |
| Loss to lease | 40 × $75 × 12 | $36,000 |
| Rent at in-place leases | $758,400 − $36,000 | $722,400 |
The building is fully occupied and still collects $36,000 a year less than its own rent roll could support. At a 6% cap rate that loss-to-lease represents $600,000 of value recoverable purely by renewing leases at market as they expire: no renovation, no repositioning, no additional tenants. This is why underwriters insist on seeing GPR built at market rather than at contract rent.
Common mistakes
- Building GPR from in-place rents
- It hides loss-to-lease, which is often the largest single value-add opportunity in a stabilized property.
- Including expense reimbursements in GPR
- Recoveries belong in other income. Mixing them in makes rent figures incomparable between net and gross lease structures.
- Using asking rents rather than achieved rents as market
- Asking rent before concessions overstates the ceiling, and every deduction below it inherits the error.
Frequently asked questions
- What is gross potential rent?
- The total annual rent a property would generate at full occupancy with every unit leased at market rent, before any deduction for vacancy, collection loss or concessions.
- What is the difference between gross potential rent and effective gross income?
- Gross potential rent is the theoretical maximum from rent alone. Effective gross income is what remains after deducting loss to lease, vacancy and collection loss, and concessions, and adding other income such as parking, laundry or expense reimbursements.
- What is loss to lease?
- The difference between market rent and the rent actually charged under existing leases. It represents income the property could earn without any change in occupancy, recovered as leases expire and renew at market.