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 |
|---|---|
| Target House Price (£) | £300,000 |
| Deposit Required (%) | 10% |
| Current Savings (£) | £10,000 |
| Monthly Savings (£) | £800 |
For those figures the calculator returns:
- Target deposit: £30,000.00
- Time to save: 1.00 years 11.00 months (23.00 months total)
Method & assumptions
This calculator shows how a regular monthly contribution, combined with an initial lump sum and assumed interest rate, will grow toward a savings target over time. It applies compound interest, assuming interest is calculated and added monthly, which reflects how most UK savings accounts operate. The Lifetime ISA bonus — where applicable — is not automatically included in the base calculation; you should factor it in separately if you are using a LISA as part of your savings strategy. Inflation is not deducted from the projected total, so the real purchasing power of your savings may be lower than the nominal figure shown if inflation is significant over the period. This tool provides an illustrative projection and should be used alongside advice from a qualified financial adviser for major purchase planning.
Common mistakes
- Assuming a constant return without checking a more conservative growth rate.
- Forgetting ongoing contributions, fees or tax wrappers where relevant.
- Focusing only on the final balance instead of the path required to reach it.
- Ignoring the drag of charges over a long period.
What to do next
- Test a cautious, expected and optimistic growth rate.
- Compare this result with related savings or retirement tools before committing more money.
- Consider charges and any tax wrapper that applies.
- If the projected balance falls short, increase the contribution until the result meets your goal.