Loss to Lease Calculator
The gap between what your suites pay and what they would achieve at market — suite by suite, with the upside and the exposure kept apart instead of netted into one flattering number. Free, no signup.
The rent roll
One row per suite, at annual rent. A suite needs both figures to count — leave either at zero and it drops out of the answer entirely.
1 of 5 rows are not in the answer, because a suite needs both an in-place and a market rent above zero. A vacancy and a suite nobody has priced drop out the same way — so this gap is over 4 occupied, priced suites, not the whole building.
Loss to lease
$4,000
1.7% below marketIn-place rent across 4 suites is $4,000 a year below what those spaces would achieve at market today.
- Gross upside (suites below market)
- $10,000 · 2
- Exposure (suites above market)
- $6,000 · 1
- In-place rent total
- $225,500
- Market rent total
- $229,500
- Suites in the answer
- 4 of 5
The headline is hiding two numbers
The $4,000 headline is $10,000 of upside across 2 suites minus $6,000 of exposure across 1. Netting them reports a number smaller than either fact, and the two behave completely differently at rollover: one is rent you can go and get, the other is rent you have to defend.
The headline number is the problem
Almost every rent roll reports loss to lease as one percentage. That percentage is a subtraction, and a subtraction treats a suite above market as cancelling a suite below it.
They do not cancel. They move in opposite directions at rollover. Rent below market is money you can go and get when the lease expires. Rent above market is money you have to defend, and usually lose, when that lease expires. One is an opportunity with a date on it; the other is a liability with a date on it. Netting them produces a number that is smaller than either.
On the rent roll below the netted answer is $4,000, or 1.7% — small enough to ignore. The two facts underneath it are $10,000 of upside and $6,000 of exposure, and those are worth working on.
What this calculator includes
Suite by suite
One row per space, because the gap is built from leases and only means something at that level.
Upside and exposure, separately
The two facts a netted percentage destroys, reported as their own numbers.
Excluded suites are named
A vacancy or an unpriced suite drops out — the tool says how many, rather than printing a gap over a partial roll.
Negative gaps are called what they are
In-place above market is exposure at rollover, not a gain.
No usable suite returns nothing
An empty answer is not a building sitting exactly at market, so it shows a dash.
The same engine as the product
Calls the code that underwrites a real deal, so the two cannot drift apart.
Example: a five-suite roll that looks like nothing
Sample inputs
- Suite 100
- $42,000 in-place · $48,000 market
- Suite 200
- $88,000 in-place · $92,000 market
- Suite 210
- $31,500 in-place · $31,500 market
- Suite 300
- $64,000 in-place · $58,000 market
- Suite 400
- vacant · $36,000 market
Four suites have both figures, so four are in the answer. They pay $225,500 against $229,500 of market rent — a gap of $4,000, or 1.7% of market. A summary would round that to “roughly at market” and move on.
Split it and the building looks different. Suites 100 and 200 are $10,000 below market between them. Suite 300 is $6,000 above it. Suite 210 is exactly at market and contributes nothing either way.
So this is not a building at market. It is a building with $10,000 of rent to chase on two suites and $6,000 of rent to defend on a third — and which of those matters more depends entirely on which lease expires first.
Suite 400 is vacant. Its $36,000 of market rent is not in the gap, and should not be: there is no lease under market there, only empty space. Counting it would book the same shortfall twice, once as loss to lease and once as vacancy.
The same roll, read two ways
| Reading | What it reports | What you would do about it |
|---|---|---|
| One netted percentage | 1.7% below market | Nothing. It rounds to noise. |
| Upside, separately | $10,000 across 2 suites | Check when 100 and 200 expire; price the renewals at market. |
| Exposure, separately | $6,000 on 1 suite | Model 300 rolling down. Do not underwrite its current rent into the exit. |
| Suites in the answer | 4 of 5 | Price suite 400, or state plainly that the gap excludes it. |
A gap is only worth what the expiration schedule lets you collect
Loss to lease has no date attached, which is what makes it so easy to oversell. The number is identical whether those leases expire next year or in 2034 — but in one case it is your money and in the other it belongs to whoever owns the building by then.
So it has to be read against the rollover schedule. The useful version of the question is not “how big is the gap” but “how much of the gap sits on leases expiring inside my hold period”. That figure is often a fraction of the headline, and it is the only part of it you can actually underwrite.
Two more things quietly inflate the number. Market rent taken from asking rates rather than signed ones runs high, and every dollar of that error lands in the gap. And a comparable’s face rent ignores the free rent and improvement allowance it took to sign — its net effective rent is lower, sometimes materially, so a gap measured against face rents is measuring against a rent nobody actually collected.
Frequently asked questions
What is loss to lease?
The gap between what a property's suites currently pay and what the same spaces would achieve at market rent today. It is normally quoted as a percentage of market rent. Positive means in-place rent sits below market, which is upside only if the leases roll soon enough to capture it.
How do you calculate loss to lease?
Total the in-place annual rent across the suites you are measuring, total the market rent for the same suites, and subtract. The gap as a percentage of the market total is the loss to lease. On a roll of four priced suites paying $225,500 against $229,500 of market rent, the gap is $4,000, or 1.7%.
Is loss to lease a good thing?
It is upside on paper and only becomes money at rollover. A large gap on leases with eight years left belongs to whoever owns the building then, not to you. The gap is worth what it is worth given the expiration schedule, so it should always be read next to WALT rather than on its own.
What is gain to lease?
The reverse — in-place rent above market, which shows as a negative loss to lease. The flattering name is misleading: it is income at risk. When those leases roll, rent moves toward market, and the difference is what the building stands to lose rather than gain.
Why does a single loss-to-lease percentage hide so much?
Because it nets. A suite $6,000 above market cancels a suite $6,000 below it and the summary reports nothing happening, when in fact there is upside to chase and exposure to defend. On the example here, a 1.7% headline is made of $10,000 of gross upside and $6,000 of separate exposure — the netted figure is smaller than either one.
Are vacant units included in loss to lease?
They should not be, and here they are not. A vacant suite has no in-place rent, so including its market rent would book the entire amount as a shortfall against a lease that does not exist — which is vacancy, a different measurement. The same rule catches an occupied suite nobody has priced: with no market rent on file, it drops out too, and the honest response is to report how many suites are actually in the answer.
How does loss to lease differ from vacancy loss?
Vacancy loss is rent forgone because space is empty. Loss to lease is rent forgone because occupied space is leased below market. A building can be fully occupied with a large loss to lease, or nearly empty with none at all, and confusing the two double-counts the same shortfall.
How is market rent determined?
From comparable leases signed recently for similar space, adjusted for the differences that matter — size, floor, condition, term, and what concessions the comparable actually carried. A market rent taken from an asking rate rather than a signed one tends to run high, and every dollar of that error lands straight in the loss-to-lease number.
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Related guides
WALT explained
The schedule that decides whether this gap is ever yours.
What is a rent roll?
The document both rent figures come from.
Net effective rent
Why a comparable's face rent overstates what it really achieved.
Lease guaranties explained
What stands behind the rent you are hoping to raise.
How to read an offering memorandum
Where a loss-to-lease claim appears, and what to check behind it.
CRE glossary
Every term, grouped by the question it answers.
The gap is worth what your expiration schedule lets you collect.
DealWise AI derives in-place rent from the leases it read, puts your market rents beside it suite by suite, and shows the gap against the rollover profile — so you can see how much of it lands inside your hold.