Illustrative estimates based on the numbers entered. Actual investment returns, lender calculations, fees and repayment schedules may differ. Not investment, lending, credit, tax or debt advice.
Visualise how compounding grows savings, investments and debt — and see how small changes reshape the outcome. Switch between growing money and paying down debt and watch the same curve turn around.
57% of the final value comes from growth rather than from money you paid in.
| Point | Projected value | Money you paid in |
|---|---|---|
| Year 0 | €10k | €10k |
| Year 2 | €21k | €19k |
| Year 3 | €33k | €28k |
| Year 5 | €46k | €38k |
| Year 6 | €61k | €47k |
| Year 8 | €77k | €56k |
| Year 9 | €96k | €65k |
| Year 11 | €116k | €74k |
| Year 12 | €139k | €83k |
| Year 14 | €164k | €93k |
| Year 15 | €192k | €102k |
| Year 17 | €224k | €111k |
| Year 18 | €258k | €120k |
| Year 20 | €297k | €129k |
Growth overtakes the money you paid in during year 17.
Results are illustrative estimates based on the numbers you enter. Actual investment returns, lender calculations, fees and repayment schedules may differ. Compoundly is not investment, lending, tax or debt advice.
Compound interest is one mechanism with two faces. On an investment, growth is earned not only on the money you paid in but on the growth that came before it, so the balance accelerates upward. On a debt, if unpaid interest becomes part of the balance, future interest is charged on the larger amount — and the balance can accelerate in exactly the same shape.
Compoundly draws both with the same visual language so the comparison is direct. In Grow money the curve climbs, and the point at which growth overtakes everything you have paid in is marked on the chart. In Pay down debt the balance falls as repayments land — or rises, when the payment does not cover the interest charged.
Every figure comes from a full period-by-period simulation, not a shortcut formula: an amortisation engine for loans, a revolving-balance engine for cards, and a compounding engine for investments. The assumptions behind each are listed under the chart and set out in full on the methodology page.
Compoundly is an illustrative calculator. It is not investment, lending, credit, tax or debt advice, and it is not a substitute for your lender's own figures.