A holiday let calculator is a screening tool. It will not tell you with certainty what a cottage, lodge, apartment or serviced accommodation unit will earn, but it can show whether the basic economics deserve more attention. For a buyer, that is the job: test the assumptions early, before survey fees, mortgage applications and emotional attachment make the decision harder.

The most useful calculators separate revenue, operating costs, finance costs and upfront cash invested. If everything is mixed into one optimistic profit number, weak deals can look stronger than they are. A clear UK holiday let model should show gross booking revenue, cleaning income, management fees, platform fees, fixed annual costs, mortgage cost, cashflow, yields and break-even occupancy.

Start with realistic booking assumptions

A simple annual occupancy percentage is rarely enough for a UK holiday let. Demand is seasonal, and the same property can earn very different weekly rates in school holidays, shoulder months and quiet winter periods. Split the year into high, mid and low season. Enter a weekly rate for each period, then enter the number of weeks you think could be booked in each period.

For example, an illustrative coastal cottage might assume 10 high-season weeks at GBP 1,650, 14 mid-season weeks at GBP 1,050 and 10 low-season weeks at GBP 650. That does not mean the property will achieve those figures. It simply makes the revenue assumption visible, so you can challenge each part and compare it with listings, agent estimates and your own risk appetite.

Separate guest cleaning fees from owner cleaning cost

Cleaning is easy to understate. Some owners see the guest cleaning fee and assume it offsets the cleaner, laundry and changeover cost. In practice, the fee charged to guests may be lower than the amount paid to the cleaning team, especially for larger cottages, hot tub properties and remote locations. A calculator should show the cleaning margin or loss instead of hiding it inside total costs.

A useful assumption is one clean per booked week. That is still simplified because short breaks can increase changeovers, but it is a sensible starting point for pre-purchase screening. If your strategy depends on frequent weekend stays, add a more cautious cleaning cost or include extra annual cleaning in other costs.

Include the costs that make holiday lets different

Holiday lets are operational businesses as much as property investments. Common costs include platform fees, booking fees, agency or management fees, utilities, broadband, insurance, maintenance, repairs, linen, waste, compliance checks, rates or council tax, service charges and replacement furniture. If there is a hot tub, spa or sauna, maintenance and energy costs need their own line.

A maintenance reserve is helpful because repairs rarely arrive in neat annual amounts. The calculator can apply a percentage of booking revenue, such as 5%, as a simple allowance. This is not a prediction; it is a buffer that stops the base case from assuming every year is unusually smooth.

Model finance separately

Net operating income before mortgage is the property result before finance. Keeping it separate helps you compare properties with different deposit sizes and mortgage structures. A deal might have strong operating profit but weak cashflow after a high-rate repayment mortgage. Another might be acceptable only with interest-only finance, which creates a different risk profile.

For interest-only finance, annual mortgage cost is estimated as mortgage amount multiplied by interest rate. For repayment finance, the payment formula includes principal repayment over the term. Neither is a mortgage quote. Treat it as an illustrative scenario until a qualified broker or lender confirms real options.

Use break-even occupancy as a safety check

Break-even occupancy asks how much revenue, or how many booked weeks, are needed to cover operating costs and mortgage cost. This is often more useful than a single return figure. If the property needs very high occupancy just to avoid losing cash, the downside may be uncomfortable even if the optimistic case looks attractive.

You can improve the test by running a worst case. Reduce rates, reduce booked weeks and increase costs. If the worst case is painful but survivable, the opportunity may be worth more research. If a small change turns the result negative, the deal may need a lower purchase price, more deposit, lower management costs or a different strategy.

Frequently asked questions

Is a holiday let calculator a forecast?

No. It is an illustrative model based on assumptions you enter. It helps compare scenarios but does not predict actual bookings or returns.

What return should I target?

There is no universal target. Buyers should consider risk, finance, tax, location, effort and alternative uses of cash. The calculator shows estimates, not advice.

Should I include tax?

For initial deal screening, many buyers model pre-tax cashflow first, then ask an accountant to review the structure and tax position before committing.

Next step: Test your own assumptions in the free holiday-let calculator, compare scenarios with the premium spreadsheet, or use the property finder alerts when you are actively searching.