Lifetime ISA calculator
See your contributions, the government's 25% bonus, and your projected Lifetime ISA balance, plus what withdrawing early would actually cost you.
Lifetime ISAs can only be opened between 18 and 39.
Capped at £4,000 a year, which works out at £333 a month.
Projected balance
Your contributions
£18,000
Government bonus
£4,500
Projected balance
£24,898
If you withdrew early
Withdrawing for anything other than a first home, turning 60 or terminal illness costs a 25% government charge on the whole balance, which is more than just clawing back the 25% bonus. It also costs 6.25% of the money you put in yourself.
25% charge
£6,225
You would keep
£18,674
For a first home: the property must cost £450,000 or less, and you must have held the Lifetime ISA for at least 12 months before completing.
How this works
- The government bonus is 25% of what you pay in each tax year, up to the £4,000 annual limit, so at most £1,000 a year. We add the bonus in the same month as your contribution, and both then grow at the rate you enter.
- Contributions and the bonus stop from your 50th birthday, even if you started before then. If your term runs past that age, we keep growing your existing balance for the remaining years without adding new money.
- If your monthly amount would take you over the £4,000 annual limit, we cap what earns the bonus at that limit and flag the monthly figure it works out at.
- Growth compounds monthly, using the same method as our other calculators.
- The "if you withdrew early" box applies the 25% government charge to your whole projected balance, as if you withdrew it all on an unauthorised basis, for any reason other than a first home purchase, turning 60, or terminal illness.
- That 25% charge is worth more than just clawing back your bonus: with no growth, it costs 6.25% of the money you contributed yourself, because the charge applies to your contribution and bonus together, not the bonus alone.
- For a first home penalty-free, the property must cost £450,000 or less, and you must have held the account for at least 12 months before completing.
- All figures are rounded to the nearest pound.
Tax treatment depends on your circumstances and may change. This is not financial advice.
Questions people ask
Who can open a Lifetime ISA?
Anyone aged 18 or over but under 40, so up to and including age 39. Once it is open, you can keep paying in and earning the bonus up to your 50th birthday.
What can I use a Lifetime ISA for without a penalty?
Buying your first home costing £450,000 or less, after holding the account for at least 12 months, or making any withdrawal from age 60, or if you become terminally ill with under 12 months to live.
What if I withdraw for another reason?
You pay a 25% government withdrawal charge on the whole amount, including your own contributions and the bonus. That costs more than just losing the bonus: it also claws back some of your own money, worth 6.25 percentage points of what you paid in at current rates.
Can I have a Lifetime ISA as well as a Cash ISA?
Yes. A Lifetime ISA counts towards your overall £20,000 ISA allowance alongside a Cash ISA, a Stocks and Shares ISA or an Innovative Finance ISA, but you can only pay into one Lifetime ISA in a tax year, up to £4,000.
Is the government planning to replace the Lifetime ISA?
A consultation on a new First Time Buyer ISA that would eventually replace the Lifetime ISA for house purchases closed on 18 August 2026, and gov.uk has not confirmed a launch date. Existing Lifetime ISAs continue as normal for now.