Comparison
Rental Break-even Across Cost Burdens: The Occupancy Required and the Vacancy It Leaves
As a rental’s fixed costs rise as a share of its scheduled rent, what occupancy does break-even require, how much vacancy is left before cash flow reaches zero, and where does full occupancy stop being enough?
The short answer
Break-even occupancy is the cost burden divided by the share of rent that survives the management fee. With no fee charged, a burden of 50% of scheduled rent needs 50.00% occupancy and leaves 26.00 weeks of vacancy. The same burden at a 20% fee needs 62.50% and leaves 19.50 weeks.
The fee also moves a ceiling. At a 20% fee, no cost burden above 80% of scheduled rent reaches break-even at any occupancy that exists — not because occupancy is hard to achieve, but because full occupancy is already not enough. These are outputs of a model, not forecasts.
- Who it applies to
- A fixed reference set of cost burdens under stated management-fee rates, with no vacancy assumed in advance and no currency anywhere. It compares ratios against each other, not properties, markets or products.
- What this does not tell you
- It does not describe what occupancy any property will achieve, how likely a vacancy of any length is, or whether a burden is high or low. Those are judgments and forecasts; these are ratios.
Model Rental Break-even and Cushion v1.0, from the same calculation the Rental Break-even and Cushion Calculator runs.
What is being compared
One question is asked of every cost burden in the same way, so the burdens can be read against each other rather than one at a time. Nothing varies between rows except the size of the burden, and nothing varies between columns except the management-fee rate.
| Cost burdens compared | 50% · 60% · 70% · 80% · 90% · 100% · 110% of scheduled rent |
|---|---|
| Stated management-fee rates | 0% · 10% · 20% |
| What the cost burden contains | Debt service in full, owner operating costs, the maintenance reserve and the CapEx reserve |
| What it does not contain | The management fee, which is charged on rent actually collected |
| Vacancy already assumed | None. Every scenario starts from a full year of scheduled rent |
| Model year | 52 weeks, with vacancy averaged across it rather than placed in it |
| Units | Ratios of scheduled rent throughout. No currency, price, yield or tax is modelled |
The three fee rates are illustrative: numbers chosen so the burdens can be compared under a stated assumption, not typical rates, market rates or claims about what any manager charges. No burden is described or implied to be normal, prudent, achievable or safe.
The relationship, written once
The calculator solves one equation for occupancy, and every figure on this page is that same equation with the currency divided out of it:
break-even occupancy = cost burden ÷ (1 − management-fee rate)
Cost burden is the fixed obligation stack as a share of scheduled rent: the full debt payment, the owner costs a tenant does not pay, and the maintenance and CapEx allowances, divided by the rent the lease schedules for the same period. The management fee is deliberately not in it, because a percentage fee scales with rent actually collected while every term in the stack does not — which is exactly why it appears in the denominator instead.
Because both sides are ratios, the size of the property drops out. A rental at ten times the rent and ten times the costs sits on the same row. That is what makes a table of seven burdens a reference rather than seven worked examples.
What the fee does to the ceiling
Occupancy cannot exceed a full year. That puts a hard ceiling on the cost burden any rental can carry — and the ceiling is not 100% unless the fee is zero.
| Management fee | Highest cost burden that can break even | Occupancy needed per unit of burden |
|---|---|---|
| 0% | 100% | 100.00% |
| 10% | 90% | 111.11% |
| 20% | 80% | 125.00% |
Read the third column as the price of a point of burden. With no fee, one unit of cost burden needs one unit of occupancy and the two run together. At 20%, the same unit needs 125.00% — the fee is charged on the rent that is collected, so rent has to be collected to pay it, and the occupancy required rises faster than the burden that caused it.
The middle column is the same fact stated as a limit, and it falls exactly as fast as the fee rises: 100% with no fee, 90% at 10%, and 80% at 20%.
The occupancy each burden requires
At a fixed fee rate the relationship is a straight line: ten more points of cost burden always cost the same number of occupancy points. What changes between the columns is the steepness of that line, and where it runs out of room.
| Cost burden | 0% fee | 10% fee | 20% fee |
|---|---|---|---|
| 50% | 50.00% | 55.56% | 62.50% |
| 60% | 60.00% | 66.67% | 75.00% |
| 70% | 70.00% | 77.78% | 87.50% |
| 80% | 80.00% | 88.89% | 100.00% |
| 90% | 90.00% | 100.00% | 112.50% — no occupancy reaches it |
| 100% | 100.00% | 111.11% — no occupancy reaches it | 125.00% — no occupancy reaches it |
| 110% | 110.00% — no occupancy reaches it | 122.22% — no occupancy reaches it | 137.50% — no occupancy reaches it |
Read a row to see what the fee rate costs at one burden, and a column to see what burden costs at one fee rate. Both readings are the point of putting the two dimensions in one table.
The vacancy each burden leaves
The same relationship, stated as the thing an owner actually experiences: how many weeks of an empty property the year can absorb before cash flow reaches zero.
| Cost burden | 0% fee | 10% fee | 20% fee |
|---|---|---|---|
| 50% | 26.00 weeks | 23.11 weeks | 19.50 weeks |
| 60% | 20.80 weeks | 17.33 weeks | 13.00 weeks |
| 70% | 15.60 weeks | 11.56 weeks | 6.50 weeks |
| 80% | 10.40 weeks | 5.78 weeks | 0.00 weeks |
| 90% | 5.20 weeks | 0.00 weeks | Not reachable — break-even needs more than 100% occupancy |
| 100% | 0.00 weeks | Not reachable — break-even needs more than 100% occupancy | Not reachable — break-even needs more than 100% occupancy |
| 110% | Not reachable — break-even needs more than 100% occupancy | Not reachable — break-even needs more than 100% occupancy | Not reachable — break-even needs more than 100% occupancy |
Every scenario here books no vacancy in advance, so the weeks the year can absorb and the headroom that remains are the same number. In a scenario that already assumes vacancy they are not, and reading the first as the second overstates the cushion — the calculator shows all three quantities separately for exactly that reason.
Where full occupancy stops being enough
Two rows in the tables above behave differently from every other row, and the difference is structural rather than a matter of degree.
- At the ceiling — 80% burden, 20% fee
- Break-even occupancy is 100.00% and the cushion is 0.00 weeks. Full occupancy is exactly break-even: the arrangement reaches zero and has nothing left over, because occupancy has a ceiling and the ceiling is now the whole of the plan.
- Past the ceiling — 110% burden, 0% fee
- Break-even occupancy is 110.00%, which is not a high occupancy — it is a number outside the range an occupancy can take. Not reachable — break-even needs more than 100% occupancy. There is no finite vacancy cushion, because the shortfall exists at every occupancy including a year with no empty day in it.
Past that boundary, vacancy is not the binding constraint. Better marketing, a faster re-let and a longer lease all address vacancy, and vacancy is not what the arithmetic is failing on. Something in the rent or in the cost stack would have to be a different number.
None of that says the boundary is a probability, a forecast, an expected vacancy level or a threshold anybody should stay below. It is where one equation stops having a solution in the range its variable can occupy, and nothing more than that.
One burden, read across the three fee rates
Take the 80% row and read it left to right. The cost burden does not move; only the fee does, and every figure below comes out of the same model run the tables above are built from.
- 0% fee. Break-even occupancy 80.00%, leaving 10.40 weeks of the year the model can absorb before cash flow reaches zero.
- 10% fee. Break-even occupancy 88.89%, leaving 5.78 weeks of the year the model can absorb before cash flow reaches zero.
- 20% fee. Break-even occupancy 100.00%, leaving 0.00 weeks of the year the model can absorb before cash flow reaches zero.
Three fee rates, one unchanged cost burden, and the last of them is a different kind of answer from the first two. That is the whole of what this reference publishes: not that one of these is good and another bad, but that a fee charged on collected rent moves both the occupancy required and the point at which any occupancy stops being sufficient.
Why the burden is measured against scheduled rent
Scheduled rent is what the lease charges for the period. Collected rent is what an occupancy of less than a full year actually produces. Every cost burden on this page is measured against the first, because the second is the quantity the table is solving for — expressing the burden as a share of collected rent would put the unknown on both sides of the equation.
The management fee sits on the other side for the same reason. It is charged on rent actually collected, so it shrinks with occupancy rather than staying fixed with the mortgage and the reserves — which is why it divides the burden rather than joining it. Why gross scheduled rent and money in the account are different quantities at all is the explainer's subject: Why Gross Rental Yield Is Not Cash Flow. This page measures how the relationship behaves across burdens rather than re-explaining its cause.
A ratio is not a verdict on a property
Two rentals on the same row of these tables require the same occupancy and may have almost nothing else in common. The row is a statement about two numbers. What actually happens depends on the lease, the tenant, the local market, what the building needs next, how the debt is structured, and how long the owner can fund a shortfall.
UBWHY publishes no threshold at which a cost burden becomes acceptable, and none of these rows is labelled good, safe, prudent or risky. A cash-flow shortfall is not automatically a bad investment — principal repayment and property-value change sit outside a cash-flow figure entirely, and people fund shortfalls deliberately in exchange for both. A wide cushion is not automatically a good one, for the same reason. Nothing on this page is a reason to buy, hold, let, refinance or sell anything.
This page belongs to a wider subject. Explore the Rental cash flow topic to see which UBWHY asset answers which question.
What this reference does not determine
The figures on this page are outputs of a UBWHY calculation model applied to the assumptions stated above. They are not market data, expected occupancy, the performance of any property, or a forecast. The reference cannot determine:
- what occupancy any property will actually achieve, which nothing here predicts
- how likely a vacancy of any length is, at any burden, anywhere
- whether a rent is achievable, lawful or sustainable in any market
- whether a cost burden is high or low, because that is a judgment and this is a ratio
- the purchase price, the gross or net yield, and the return on capital, all excluded by the model
- principal repayment and property-value change, which sit outside a cash-flow figure entirely
- tax of any kind, and no wrapper, allowance, jurisdiction or rate is modelled
- inflation and rent escalation, so every ratio here is held constant
- the timing of a vacancy, a repair or an arrears month, none of which this model places
- whether owning, letting, selling or refinancing is appropriate for any particular person
The model is a steady-state monthly equivalent. It places no vacancy in a calendar, simulates no consecutive empty months, carries no arrears, holds no reserve balance and amortises no mortgage — so a year that matches one of these rows on average can still be a year an owner has to fund out of something else.
None of this is financial, legal or tax advice, and no product, provider or property is recommended, ranked or named anywhere on this page.
Where these figures come from
Every number above is produced by Rental Break-even and Cushion v1.0, the same calculation model behind the Rental Break-even and Cushion Calculator, run at build time over the reference set at a scheduled rent of one unit. Nothing on this page is typed by hand, and no second formula was written to produce it.
Two of the published cells are additionally reproduced by the model's own verified test cases — RB-4 for the break-even occupancy and the absorbable vacancy at a 50% burden and a 10% fee, and RB-2 for the 110.00% break-even occupancy and the unreachable state at a 110% burden with no fee — which are recalculated independently on every build. The remaining figures are pinned by exact regression tests against the same model.