Cash Flow Calculator
Project monthly and annual net cash flow, before and after tax.
Introduction
Who this is for: Landlords assessing whether a property genuinely pays its way.
Why it matters: Since Section 24, individual landlords cannot deduct mortgage interest from rental income — they receive a 20% tax credit instead. Higher-rate taxpayers are therefore taxed on income they never actually keep, which is why many properties that look profitable pre-tax are not.
Typical scenario: A higher-rate taxpayer checking real post-tax cash flow on a leveraged buy-to-let.
- Modelling pre-tax cash flow only, which for higher-rate individual landlords is misleading.
- Forgetting Section 24 applies to individuals but not limited companies.
- Omitting a capex reserve — boilers and roofs are not optional.
Inputs
Income
Costs
Tax
Analysis
Effective rent of £14,250 less £12,850 of costs gives £117 monthly pre-tax. After £2,120 of tax (individual basis), that becomes £-60 a month.
This analysis provides context, not financial advice. Consult a qualified adviser before making investment decisions.
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Sensitivity
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Live Results
Monthly Cash Flow (pre-tax)
£117
Monthly Cash Flow (post-tax)
£-60
Annual Cash Flow (post-tax)
£-720
Annual Tax
£2,120