What is a good stress test?

Use scenarios that would be uncomfortable but plausible for your household, then try a harsher version. The goal is to reveal dependencies, not predict one exact event.

What if the stressed margin is still positive?

That is useful, but check whether all essential costs are included and whether the shock lasts longer or involves a larger one-off cost.

What should I do if the runway is short?

Possible responses include building accessible cash, reducing fixed commitments, reviewing insurance or increasing income resilience. If priority bills are already at risk, seek appropriate support now rather than waiting for a simulated threshold.

Money optimisation

Household Financial Stress-Test

A normal-month budget can look healthy while still being vulnerable to a short interruption in income or a large essential expense. This tool asks what happens when several things go wrong at once.

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Your estimate

Use the result as a planning guide and change inputs to test the assumptions that matter most.

How this calculator works

The model starts with your normal monthly margin, then reduces income by your selected percentage, increases essential spending, applies a one-off shock to accessible cash and estimates the recurring shortfall and cash runway.

How to use it

Enter normal take-home income and committed monthly costs.
Add accessible emergency savings.
Choose an income-drop and essential-cost-rise scenario.
Add a one-off shock such as a repair or excess.
Test how long the scenario lasts and note when the household would need action.

Assumptions and limitations

This is a simple static stress test. It does not include benefits, insurance payouts, redundancy pay, credit availability, changing interest rates or costs you could reduce during the shock.

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