About Rent Calc

Rent Calc is a scenario calculator for assessing a flat to let and comparing capital decisions.

For each scenario, you can set the initial spend, the expected rent, recurring costs, taxes, vacancy, rental growth, and the alternative use of spare cash.

The result shows not only monthly rent, but final capital over the selected horizon.

• compare renting the flat as is, a light cosmetic refresh, furniture, appliances, and a stronger refurbishment;
• understand whether a higher rent justifies the additional spend;
• consider intermediate options instead of only choosing between refurbishment and savings;
• compare renting with the sale alternative, where the full capital works in savings;
• see the effect of compound return when spare cash flow is moved into savings;
• compare scenarios across short and long horizons.

Rent Calc is not only for the question “should I refurbish or not”.

It can be used when you receive keys to a new build, prepare a flat after tenants move out, assess a resale purchase, consider a light cosmetic refresh, or compare renting with selling.

In each situation, the user builds several scenarios and compares them in one model.

For example: rent as is, do a light cosmetic refresh, add furniture and appliances, fully prepare the flat for rent, do a stronger refurbishment, or compare with the full-capital savings benchmark.

• refurbishment, light cosmetic refresh, furniture, appliances, and property preparation costs;
• the expected rent after the change;
• taxes and recurring operating costs;
• utilities, commissions, and property management fees;
• a reserve for future repairs and upkeep;
• rental growth and property value growth over time;
• the placement of spare cash flow into savings with compound return.

The user defines the property, spare capital, savings rate, and calculation horizon.

Then they configure several preparation and rental scenarios.

After the calculation, the scenarios are compared against each other, the base case, and the savings benchmark.

In Rent Calc, this option is read through the savings benchmark for the full capital.

It shows what the result would be if the flat were treated as sold and the full capital worked in savings at the selected rate.

This makes it possible to compare two approaches: keep the capital in the property and earn rent, or move the capital out of the property and earn savings return.

• the scenario's final capital on the chosen horizon;
• net cash flow after taxes, vacancy, and recurring costs;
• the payback period for additional spend;
• the difference versus the base scenario and savings benchmark;
• cash flow, final capital, difference, payback, and scenario result as the main terms.

On the results page, scenarios are shown both in a table and in charts.

The charts show spend and payback, net flow dynamics, and the comparison against the savings benchmark.

The user does not get a vague answer like “worth it” or “not worth it”. Instead, they get a comparison of several scenarios in one model.

That makes the decision more concrete: not a feeling about refurbishment or rent, but a discussion based on assumptions, metrics, and planning horizon.

Rent Calc is designed so the calculation can act as structured context for AI analysis.

There is no built-in AI chat in the current version.

• registration and a personal account are not available yet;
• the number of scenarios is fixed: the current setup uses 5 scenarios;
• one scenario is the base case: CAPEX = 0, used as a comparison point;
• there is no built-in AI chat for result analysis yet;
• the calculation depends on the entered parameters and is not financial, tax, or legal advice.

Rent Calc was created by STIV Labs as an applied tool for scenario modelling and decision support.

STIV Labs is the author and developer of the product.