Sub-Letting Profit Calculator

What this subletting profit calculator models

Compare potential sublet income with the rent and costs you enter. The result is a modeled monthly profit or loss, plus a twelve-month annualization of that same monthly scenario. It does not decide whether a property or arrangement is suitable, permitted, profitable in practice or a good investment.

Enter the six primary assumptions first: base rent, full-occupancy potential income, utilities, cleaning/management, other recurring costs and occupancy. The default example uses EUR as a label, rent 1,500, potential income 2,400, utilities 150, cleaning 100, other costs 50 and occupancy 85%. These are illustrative assumptions, not market data. Advanced costs, setup allocation and reverse tools start inactive.

Potential income at 100% occupancy versus effective income

Potential monthly sublet income at 100% occupancy is the full-occupancy revenue assumption before platform fees. Effective monthly income = potential income × occupancy ÷ 100. For example, a potential 2,400 at 85% occupancy produces 2,040 of effective income.

Do not enter an amount already reduced for vacancy: the calculator would reduce it again. This is a proportional monthly model. It does not model booking calendars, nightly-rate changes, minimum stays, seasonal demand or varying month lengths.

Monthly cost and profit methodology

Base recurring costs = rent + utilities + cleaning/management + other recurring costs. Add configured fixed advanced allowances and any enabled setup allocation to obtain fixed monthly costs. Percentage platform costs = effective income × fee percentage ÷ 100. Total modeled monthly costs = fixed monthly costs + percentage costs.

Modeled monthly profit = effective income − total modeled monthly costs. Annualized profit = monthly profit × 12. Negative amounts remain losses; they are never floored at zero. Fixed monthly costs remain unchanged across occupancy scenarios, even at zero occupancy. Annualization repeats this monthly assumption; it does not model a calendar-year forecast or automatically stop setup allocation after its planning horizon.

Modeled profit margin = monthly profit ÷ effective income × 100. The denominator is occupancy-adjusted income, not potential income or cost. With zero effective income, margin is undefined, including when both income and costs are zero.

Fixed and percentage platform fees

Choose no fee, a fixed monthly fee, or a percentage of effective sublet income under Advanced monthly costs. A fixed fee remains the same at every occupancy. A percentage fee falls when effective income falls. The selected mode is used in profit, annualization, break-even occupancy, all occupancy scenarios and both reverse tools.

The fee percentage can be 0–100%. At 100%, the fee consumes all effective income, leaving profit equal to the negative fixed costs. A value above 100% is outside this model and rejected. Switching fee mode resets its value to zero, or blank for no fee, so an amount is never silently reinterpreted as a percentage.

One-time costs and optional budgeting allocation

Furnishing/setup, deposit/setup and other one-time amounts are summed separately. They do not affect operating profit unless you explicitly enable a monthly budgeting allocation. Enabling it requires a whole planning horizon of 1–600 months; 12, 24 and 36-month shortcuts are available alongside custom entry.

Monthly setup allocation = total entered one-time costs ÷ planning months. The same allocation then participates in the cost breakdown, scenarios and reverse calculations. This is a budgeting convention, not accounting or tax amortization. A deposit entry is a funding assumption: the tool does not determine whether it is an expense, refundable or recoverable, and it models no later refund.

Break-even occupancy and values above 100%

Let G be potential monthly income, O occupancy as a decimal, p the active percentage fee as a decimal, and F fixed monthly costs including any setup allocation. Profit = G × O × (1 − p) − F. If G × (1 − p) is positive, break-even occupancy = F ÷ [G × (1 − p)] × 100%.

Break-even is not capped at 100%. A result of 112% means the entered assumptions do not break even even at full occupancy. If G is zero or p is 100%, the denominator is zero: positive fixed costs mean no break-even occupancy; zero fixed costs mean every occupancy level breaks even. Zero fixed costs with a positive denominator produce a defined 0% break-even.

Occupancy comparisons and largest-cost observation

The scenario table reruns the same central model at 50%, 60%, 70%, 80%, 90% and 100%, plus your entered occupancy without duplicate rows. It preserves the selected platform-fee mode, fixed costs and setup allocation. The entered row is labeled in text as well as highlighted. No scenario is assigned a likelihood.

One observation identifies the largest active monthly cost using the current amount, including a calculated percentage fee or setup allocation. Ties use this order: base rent, utilities, cleaning/management, other recurring costs, platform fee, insurance, maintenance, tax allowance, setup allocation. If every configured cost is zero, the observation says so. It is a comparison, not spending advice.

Target-profit and maximum-rent reverse calculations

The optional target monthly profit tool solves required potential monthly income = (target profit + fixed monthly costs) ÷ [occupancy decimal × (1 − percentage fee decimal)]. It uses your selected occupancy and the same cost assumptions. It does not determine what to charge, achievable income, market pricing or legal rent limits.

With zero occupancy or a 100% percentage fee, a positive target plus fixed costs has no solution. If both target and fixed costs are zero, any supported potential income yields that zero target; there is no unique solution. A finite answer above the 10,000,000 potential-income input limit is shown explicitly as outside the supported input range, rather than silently capped.

For the desired monthly profit buffer, modeled maximum rent = effective income − percentage costs − non-rent fixed costs − desired profit. Non-rent fixed costs include every configured fixed allowance, fixed platform fee and setup allocation. The currently entered base rent is replaced for this solution, not deducted twice. If the answer is negative, the target cannot be achieved even at zero base rent; no negative maximum rent is presented.

Worked example

The default EUR-labeled example has potential income 2,400 × 85% = 2,040 effective income. Fixed monthly costs = 1,500 + 150 + 100 + 50 = 1,800. Profit = 2,040 − 1,800 = 240 per month; annualized profit = 2,880. Margin = 240 ÷ 2,040 × 100 = 11.764705882…%, displayed as 11.764706%. Break-even occupancy = 1,800 ÷ 2,400 × 100 = 75%.

Adding a 10% platform fee produces 204 of fees, 2,004 total monthly costs and 36 of modeled monthly profit. Break-even becomes 1,800 ÷ (2,400 × 0.9) × 100 = 83.333333…%. With this fee, a target profit of 300 at 85% occupancy requires potential income (300 + 1,800) ÷ (0.85 × 0.9) = 2,745.098039…; the modeled maximum rent for a 300 buffer is 2,040 − 204 − 300 non-rent costs − 300 target = 1,236.

If setup costs total 2,400 and you enable a 12-month allocation, another 200 enters monthly costs. In that same 10%-fee example, monthly profit becomes −164, annualized loss −1,968, and break-even occupancy 92.592592…%. Disabling allocation restores the operating result; the entered one-time total remains separate.

Sub-Letting Profit Calculator FAQ

How is subletting profit calculated?

Potential income times occupancy gives effective income. Subtract all configured monthly costs, including the selected platform fee and any enabled setup allocation. A negative answer is displayed as a modeled loss.

What does potential income at 100% occupancy mean?

It is your full-occupancy monthly revenue assumption before platform fees. Do not pre-adjust it for vacancy because occupancy is applied by the engine.

How does occupancy affect profit?

It scales effective income and percentage fees. Rent, fixed allowances and enabled setup allocation remain fixed. The scenarios illustrate the arithmetic, not expected demand.

How is break-even occupancy calculated?

Fixed monthly costs are divided by potential income after its percentage-fee reduction, then multiplied by 100. If the denominator is zero, the result explicitly distinguishes no break-even from every occupancy breaking even.

Why can break-even occupancy exceed 100%?

It means full-occupancy income after percentage fees is still below fixed costs. The model shows the uncapped analytical answer and explains that the assumptions do not break even at 100%.

How do percentage platform fees affect the estimate?

They apply to effective income after occupancy, so they vary in every scenario and both reverse tools. A fixed monthly fee is instead part of fixed costs. A 100% fee leaves no income contribution to cover fixed costs.

How are one-time furnishing/setup costs handled?

They remain separate unless you enable a budgeting allocation and enter a positive whole planning horizon. Only total setup costs divided by that horizon enter monthly profit. This is not tax amortization and does not model a deposit refund.

How does the target-profit calculator work?

It solves for potential income at your entered occupancy while retaining all configured costs. Zero occupancy or a 100% fee can produce no solution, or no unique solution for a zero target with zero fixed costs. An answer is not a price recommendation.

What does modeled maximum rent mean?

It is the largest base-rent amount compatible with your desired modeled profit buffer after all other configured costs. If the target fails even at zero rent, the tool explains that instead of showing a negative maximum rent.

Does this determine whether I am legally allowed to sublet or calculate my taxes?

No. It evaluates neither permission nor legal, lease, insurance or tax rules. Any tax allowance is your own planning assumption. No location is collected and no values are automatically sent to a tax calculator.