The snowball effect: what could your investments be worth?
Compounding can make time extraordinarily valuable—but the famous examples often hide the assumption doing most of the work. Here is what really determines the result.
Test · Calculator 08
Which assumptions change your financial future most?
Put returns, fees, inflation, earnings and property growth on a common visual scale, then test each assumption independently.
1 Enter your figures2 Review assumptions3 Explore the result
Your figures
Your entries stay in this tab and are not sent to Money Considered. A shareable link includes only the assumptions shown in its URL.
Starting investment after 20 years · today’s money
£73,239£120,010 in future pounds after the return and fee assumptions.Property · today’s money£317,391£520,082 future pounds
Annual income · today’s money£49,600£81,275 future pounds
£100,000 cash purchasing power£61,027No cash interest modelled
A common starting line
Every line begins at 100. Values above 100 have grown faster than inflation; values below 100 have lost purchasing power. This makes unlike amounts comparable without pretending that income, property and investments are the same thing.
Hover over or focus a point to see its exact value.
One-point test
Which assumptions carry the result?
Each row changes only that assumption by one percentage point. Annual fees stop at 0% on the lower side.
Assumptions used
- Every rate remains constant for the selected horizon.
- Investment return and the annual percentage fee are combined multiplicatively once a year.
- Property value and annual income are shown separately and do not include debt, tax or spending.
- Today-money values divide future pounds by the cumulative inflation assumption.
- The lines are deterministic illustrations, not ranges, forecasts or probabilities.
The lab is designed to expose sensitivity, not to tell you which assumptions are likely or which asset to choose. Test values that are deliberately less comfortable as well as those you expect.