Short answer: Loss to lease is the difference between market rent and the rent tenants actually pay under their current leases, for occupied units. It's calculated unit by unit, as market rent minus in-place rent, then totalled. It's usually shown as a dollar amount and as a percentage of occupied market rent or gross market rent. Units leased above market create gain to lease, which many reports net against the loss. The number is only as reliable as the market rent behind it. Loss to lease is not vacancy and, in many reports, not concessions; those are tracked separately. A rising loss to lease usually means renewal pricing is lagging the market. A falling one may mean the market has cooled, or that renewals are catching up.

Loss to lease is a rent metric that estimates the gap between current in-place rents and market rent for occupied units. It doesn't show up in collections or occupancy. It only appears when someone compares every lease to the market, which is why it's easy to overlook.

Must Read: Economic Occupancy vs Physical Occupancy

Table of Contents

1. The Formula

2. Worked Example: A Six-Unit Rent Roll

3. Gain to Lease

4. The Market Rent Problem

5. Loss to Lease vs Vacancy and Concessions

6. Where It Shows Up

7. Reading the Trend

8. Using It in Renewal Pricing

9. Loss to Lease in Acquisitions

10. Where Loss to Lease Can't Simply Be Closed

11. Checklist

12. Common Mistakes

13. FAQs

14. Conclusion

The Formula

For each occupied unit:

Loss to lease = Market rent − In-place (contract) rent

Then total across occupied units. Common ways to express it:

Some reports call "all units at market" gross potential rent. Others calculate GPR using leased rents for occupied units, in which case loss to lease is already removed from it. Check which one your reports use before picking a denominator, then use it consistently. Comparing one property's occupied-basis figure with another's gross-market-rent figure is misleading.

Worked Example: A Six-Unit Rent Roll

• Gross loss to lease (units below market only): $80 + $150 + $100 = $330
• Gain to lease (unit 103): $60
• Net loss to lease: $270 per month, or $3,240 a year
• Occupied basis: $270 ÷ $8,300 = 3.25%
• Gross market rent basis: $270 ÷ $10,200 (all six units at market) = 2.65%

Unit 203 isn't loss to lease. It's vacancy, a different loss with a different fix.

Gain to Lease

When a lease is above current market rent, the difference is gain to lease. It typically appears when:

• Market rents have softened since the lease was signed.
• A premium was charged for a specific unit or short term.
• Market rent assumptions are out of date or set too low.

Many reports net gain against loss. Showing gross loss and gain separately is more informative. A $270 net figure can hide $330 of below-market leases that could be repriced, and $60 of above-market leases that may be at risk at renewal.

The Market Rent Problem

Loss to lease is only as good as the market rent used. Common sources:

Whichever you use, document the source and date, update it on a schedule, and use the same source across properties you compare. An overstated market rent makes loss to lease look like a large opportunity. An understated one hides it.

Loss to Lease vs Vacancy and Concessions

These are often presented together but mean different things:

Reporting conventions for these lines vary. NAA's CAM financial terms and formulas guide, for example, lists concessions as a separate component of vacancy and collection loss, and NAA has described gross potential rent in more than one way across its guides. Some calculations value occupied units at leased rent and others at market rent. Whichever convention your reports follow, state it, and keep concessions and loss to lease as separate lines.

Where It Shows Up

• Income statement or T-12: often as a line between market-based rent and net rental income. See the quarterly lender reporting package.
• Rent roll: where it's actually calculated, unit by unit.
• Economic occupancy: as one of the losses, when the denominator is based on market rent.
• Budget and reforecast: as the revenue still to capture through renewals.

Reading the Trend

Track it monthly, by property and unit type, alongside market rent. A trend in loss to lease without the market rent trend next to it is hard to interpret.

Using It in Renewal Pricing

Loss to lease is mostly recovered at renewal, so the useful view is loss to lease by lease expiration month:

• Units expiring in the next 60–120 days with the largest gap are the pricing decisions that matter most.
• Month-to-month tenants often carry the widest gaps because no renewal decision ever forces a review.
• Closing the whole gap at once isn't always right. Turnover, vacancy and turn costs can exceed the rent gained, so many operators phase increases.

This works only if renewal dates are tracked reliably. See tracking critical lease dates across a portfolio. Bringing market rent, in-place rent and expiration dates into one view, for example through renewal management linked to lease and rent data, makes the per-unit gap visible when the renewal decision is made.

Loss to Lease in Acquisitions

Buyers often look at loss to lease as embedded upside: the rent that could be captured as leases roll to market, sometimes called mark-to-market. Before relying on that, check:

• How market rent was set in the seller's figures, and whether you agree.
• Whether the gap can legally be closed, given rent caps, regulated or affordable units, and lease terms.
• The lease expiration schedule: how quickly the gap could realistically burn off.
• Gain to lease units that may reprice downward.

These checks fit into operational due diligence for a property acquisition.

Where Loss to Lease Can't Simply Be Closed

Some gaps aren't fully recoverable, and reporting them as "loss" can mislead:

• Rent-capped units. For example, California's Tenant Protection Act generally limits increases for covered units to 5% plus the change in the cost of living, or 10%, whichever is lower, in any 12-month period, with exemptions (Civil Code §1947.12). Many cities and some other states have their own rules.
• Regulated or affordable units, where rent is limited by a program or regulatory agreement rather than the market.
• Leases with fixed increases that run for several years.
• Commercial leases, where market rent matters mainly at expiration or option dates.

Many teams report these units separately, or measure them against the maximum allowable rent rather than market rent.

Checklist

• Market rent source documented, with a date
• Market rent updated on a set schedule
• Loss to lease calculated per occupied unit from the rent roll
• Vacant units excluded
• Gross loss and gain to lease shown separately
• One denominator (occupied or gross market rent) used consistently
• GPR convention in your reports confirmed (market rent or leased rent for occupied units)
• Concessions treated consistently and disclosed
• Loss to lease reviewed by lease expiration month
• Month-to-month units reviewed
• Rent-capped and regulated units reported separately
• Trend tracked alongside market rent

Common Mistakes

• Including vacant units. That's vacancy, not loss to lease.
• Only reporting the net figure. Gain to lease hides part of the gap.
• Stale or inflated market rent. The metric then measures the assumption, not the property.
• Mixing denominators across properties. The comparison stops meaning anything.
• Dividing by a GPR that already uses leased rents. Loss to lease is then partly removed from the denominator, and the percentage is understated.
• Treating all of it as recoverable. Rent caps, regulated units and fixed increases may limit what can be captured.
• Pushing every unit to market at once. Turnover can cost more than the rent gained.
• Ignoring month-to-month tenants. They often carry the biggest gaps.

FAQs

1. What is loss to lease?
The difference between market rent and the rent tenants actually pay under their current leases, for occupied units.

2. How do you calculate loss to lease?
For each occupied unit, subtract in-place rent from market rent, then total the results. It's often also shown as a percentage of occupied market rent or of gross market rent.

3. What is gain to lease?
The amount by which an in-place rent exceeds market rent. Many reports net it against loss to lease, though showing both separately is more informative.

4. Is loss to lease the same as vacancy?
No. Loss to lease applies to occupied units paying below market. Vacancy is rent lost on units with no paying tenant.

5. Are concessions part of loss to lease?
In many reports, no. Concessions are tracked as a separate loss. Conventions vary, so state which approach is used.

6. What is a good loss to lease percentage?
There's no single benchmark. It depends on market direction, renewal strategy, lease terms and any rent regulation. The trend and the reasons behind it usually matter more than the level.

7. How do you reduce loss to lease?
Mainly through renewal and new-lease pricing that reflects current market rent, reviewed by lease expiration month, while weighing the cost of turnover.

8. Why does loss to lease matter in an acquisition?
Buyers may see it as upside that can be captured as leases roll to market. That depends on market rent assumptions, lease expirations and any rent caps or regulations.

Conclusion

Loss to lease turns the rent roll into a pricing question: how far is each lease from market, and when can that gap close? Calculate it unit by unit, show gross loss and gain separately, be honest about market rent, and read it by expiration month. Then it stops being a line on the T-12 and becomes a list of renewal decisions.

Note: This article is for general information only and isn't legal, financial or accounting advice. Rent regulation, reporting conventions and lease terms vary by jurisdiction and property. Confirm your approach with a qualified professional.