Why do free calculators show higher returns?

Many prioritise simplicity and use only rent and price, leaving out costs that reduce net return.

Which cost is commonly omitted?

Maintenance is frequently omitted or modelled too low, especially for older properties.

Should stamp duty be included?

Yes, it is capital outlaid to acquire the asset and should be considered when analysing return on total capital.

Property investment calculator mistakes that overstate returns

The common omitted costs and optimistic assumptions that make a property investment projection look safer than it is.

Five common errors

A headline gross yield can hide property costs. Maintenance may be omitted or set unrealistically low. Zero vacancy assumes every week is paid. A single capital-growth rate hides downside scenarios. Stamp duty, legal fees and inspections may be left out of the total capital invested.

A more honest calculation

Use net yield as the main return figure, base maintenance on the property's age and condition, include a realistic vacancy allowance, show conservative, moderate and optimistic growth cases, and include acquisition costs in the capital base.

Keep assumptions visible rather than hiding them in one output.
Compare estimates with actual costs after purchase where possible.
Obtain professional financial, tax and legal advice for a real decision.

Where YieldFrame fits

YieldFrame is designed to keep property-analysis assumptions editable and visible while comparing scenarios. It does not predict returns, provide financial advice or remove investment risk.

Published 2026-08-31. Updated 2026-08-31. Information is educational and does not replace professional advice.