Useful next calculations
When to use this calculator
- Before choosing between saving, investing or changing a contribution.
- When you want to compare cautious, base and optimistic return assumptions.
- When you need a projection before making a longer-term decision.
- When you want to see whether starting earlier or contributing more changes the outcome more.
A worked example
These are the example figures the calculator opens with.
| Input | Value |
|---|---|
| Present Value (€) | €10,000 |
| Annual Interest Rate (%) | 6% |
| Years | 10 |
| Compounds Per Year | 12 |
For those figures the calculator returns:
- Future value: €18,193.97
- Present value: €10,000.00
- Total gain: €8,193.97
- Rate: 6.00%
- Years: 10
Method & assumptions
This calculator uses the standard future value formula, applying compound interest to either a one-off lump sum, regular contributions, or a combination of both. You can adjust the compounding frequency to match your investment product — annual compounding suits most stocks and shares investments and ISAs, while monthly suits savings accounts that compound interest monthly.
The calculator assumes a fixed rate of return throughout the period, which is a simplification. In practice, investment returns vary each year. For long-term equity investments, many UK planners use a 5–7% nominal annual growth assumption before charges. Always deduct your platform and fund charges from the return rate to model a net figure. This tool does not account for tax, inflation, or changes in contribution levels over time.
Common mistakes
- Using an assumption that is not supported by a current local quote, bill, statement or official source.
- Treating a generic estimate as a lender, provider, payroll or tax authority decision.
- Mixing monthly and annual inputs without converting them consistently.
- Testing only one scenario instead of checking how a cautious assumption changes the result.
What to do next
- Run a second scenario with a cautious assumption so you can see the downside clearly.
- Compare the result with the related calculators below before making a decision.
- Check current local rules, eligibility and provider terms before applying or committing money.
- Keep a record of the assumptions so you can update the estimate when a quote, bill or pay figure changes.