Rent out or sell?

Gross yield is the simplest calculation and the least informative: annual rent divided by the market value of the property. It is useful for comparing one property against another, but it says nothing about what the owner actually receives.

Net yield subtracts the costs that continue whether or not there is a tenant: service charges, IMI (imposto municipal sobre imóveis, the annual municipal property tax), buildings insurance and maintenance. Maintenance is the cost most often understated, because it does not fall due every year; the field is pre-filled with an annual estimate and can be edited.

Void periods get a field of their own. One month a year without a tenant removes roughly eight per cent of annual income, and it is a realistic assumption between contracts. The calculation applies the months actually let to the income while keeping fixed costs whole, which is how it works in practice.

Then IRS. On residential lettings the rate depends on the length of the contract: 25% on the shortest, falling to 5% on contracts of twenty years or more. Because costs borne on the property are deductible against rental income, the rate applies to income already net of them.

The sliding scale by duration turns the term of a contract into an economic variable rather than a purely legal one. Over a few years, the gap between a short contract and a long one can be worth more than a rent increase the market may not accept anyway.

Further reductions exist that this simulator does not apply, because they depend on the history of each contract: every renewal of equal length takes another two points off the rate, up to a limit, and there is a reduction for new contracts let below the rent of the previous contract on the same property.

The moderate rent regime, aimed at residential lettings below a set monthly figure, is available as an option. We left it switched off by default because it is recent and its conditions are still settling: turn it on only if you know your case qualifies.

Letting produces an annual income and keeps you exposed to whatever the property does in value. Selling releases capital today and closes that exposure. No single number arbitrates between the two, because they measure different things.

What can be done is to look at both sides in the same detail. Set the net annual income you obtain here alongside the net figure a sale would leave you, and the decision rests on two comparable quantities rather than an instinct.

To those figures you then add what no simulator captures: your time horizon, your need for liquidity, your tolerance for managing a tenancy, and what the property means to you.

The values used are those in force in 2026 and are reviewed annually.