Useful next calculations
Rates and sources, 2026/27
Lifetime ISA contribution and government-bonus rules. The projected return, if any, is entered by you and is not a rate forecast.
| Band or figure | Rate |
|---|---|
| Annual LISA contribution cap | £4,000 |
| Government bonus | 25% of eligible contributions |
| Maximum annual bonus | £1,000 |
| First-home price limit | £450,000 |
Source: GOV.UK — Lifetime ISA. Source checked for 2026/27.
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 |
|---|---|
| Planned LISA contribution each tax year (£) | £4,000 |
| Contribution horizon (years) | 5 years |
| Current LISA balance (£, optional) | £0 |
| Assumed annual return (%) | 0% |
For those figures the calculator returns:
- LISA contributions modelled: £20,000.00
- Government bonus: £5,000.00
- Projected balance: £25,000.00
- Above annual LISA limit: £0.00
Method & assumptions
This UK-only planner applies the published 25% Lifetime ISA government bonus to the first £4,000 entered for each modelled tax year. It can also apply an annual return you choose, but that return is only an assumption: investments can fall as well as rise and provider charges are not modelled.
It does not decide whether you can open, contribute to, use or withdraw from a Lifetime ISA. GOV.UK sets conditions including opening the account before age 40, contribution and bonus eligibility until age 50, a £450,000 first-home limit and a 12-month holding period for a qualifying first-home purchase. Check the current rules, your provider and a conveyancer or regulated adviser where appropriate.
Official references
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.