Calculation methodology

Acquisition basis

Purchase price + transaction tax + buying costs + refurbishment + applicable finance costs

Mortgage-specific acquisition costs are excluded when a purchase is marked as cash.

Capital definitions

For Buy to let, Capital required is the purchase deposit plus acquisition costs. For a cash purchase it is the full purchase price plus non-finance acquisition costs. This is the denominator used for cash-on-cash return and return on capital.

For BRRR, Capital after refinance is acquisition basis plus modelled rent lost before letting, less refinance proceeds. If refinance proceeds exceed that amount, DealStack displays the excess as Capital released. It does not show a negative cash-invested balance or calculate a negative/undefined ROCE; ROCE is shown as N/A because there is no positive retained-capital denominator.

Rental performance

Monthly net income deducts mortgage payment, management, maintenance, void allowance, insurance and all applicable itemised operating costs. Gross yield uses purchase price. True gross yield uses the complete acquisition basis. Return on capital divides annual net income by positive capital employed.

Inputs labelled £/month are monthly amounts. Professional BTL inputs labelled £/year are annual amounts and are divided by 12 exactly once. The main Insurance input is monthly and is converted to an annual amount only when passed into the professional BTL engine.

Finance

Interest-only payments use loan × annual rate ÷ 12. Repayment payments use the standard amortising-loan formula. Bridge costs use purchase loan, bridge rate, holding months and arrangement fee. BRRR refinance proceeds use the conservative refinance value after any selected valuation haircut, multiplied by refinance LTV. Professional BTL current LTV uses the modelled purchase loan divided by the entered current market value.

Projections and evidence

Five and ten-year projections compound only the user’s rent-growth, cost-inflation and appreciation assumptions. They are scenarios, not forecasts. Comparable medians remain user-supplied evidence and are not independently verified.