Financial decision guide and interactive simulator

Bonus and windfall calculator

What should a lump sum do before lifestyle spending begins?

What this calculation is designed to show

A windfall may need to cover tax before it can be allocated. The remaining amount can be compared across urgent debt, emergency savings, near-term goals and long-term investing.

How to test the decision

Reserve uncertain tax first, then compare guaranteed interest saved on debt with uncertain investment growth. Avoid turning a temporary windfall into a permanent monthly commitment.

Using the result responsibly

Change one important assumption at a time and compare a cautious case with the expected case. The interactive calculator below updates from the values you enter. Its output is an educational estimate, not financial, tax, legal or investment advice.

Read the calculation methodology or learn about The Finance Check.