Your deposit is only part of the cash you need
Buyers often save for the deposit and then realise they also need money for solicitors, a survey and stamp duty. This calculator keeps three amounts apart: the deposit that goes towards the price, the buying costs, and the reserve you want left in the bank after you move in. Only the deposit reduces your mortgage.
A complete savings goal, step by step
- Deposit: 10% of a £350,000 home is £35,000, leaving a £315,000 mortgage at 90% LTV.
- Buying costs and reserve: £10,000 of costs plus an £8,000 reserve brings the total cash goal to £53,000.
- Gift: £5,000 from family brings your own target down to £48,000.
- Time to save: with £36,000 already saved, the £12,000 gap takes 16 months at £750 a month.
This assumes prices and costs stay the same while you save.
Compare deposit bands, fees included
The comparison table changes the deposit percentage but keeps your buying costs and reserve the same, so you can see the full cash needed at each band. A bigger deposit lowers your loan and LTV, but the calculator doesn’t look up mortgage deals or predict your rate. Check real deals at each band, as a lower LTV doesn’t always mean a cheaper deal once fees are counted.
Include the right property tax
Stamp Duty Land Tax applies in England and Northern Ireland, Land and Buildings Transaction Tax in Scotland and Land Transaction Tax in Wales. Choosing a nation changes the tax name and guidance, but the calculator doesn’t work out the bill or check whether you qualify for first-time buyer relief. Work out the amount using GOV.UK (England, Northern Ireland and Wales) or Revenue Scotland, then enter it as a buying cost.
Gifts, reserves and the timeline
A gift reduces how much you need to save yourself. The calculator doesn’t check whether your lender will accept it, and it doesn’t treat a family loan you’ll repay as a monthly cost, though a lender will.
Your reserve is money you keep after completion, not money you spend. The timeline divides your remaining gap by your monthly saving and rounds up to whole months. It leaves out savings interest and price changes, so update the plan if your costs, target date or family help change.
UK mortgage deposit calculator questions
What happens to my deposit if the valuation comes in below the price?
The lender bases your loan on the lower figure, so you have to cover the gap. If you agree £350,000 but the home is valued at £340,000, a 90% mortgage is £306,000, and you’d need £44,000 instead of £35,000. You can renegotiate the price, find the extra cash or accept a higher LTV if the lender allows it.
Can I use a Lifetime ISA for my deposit?
Yes, if you’re a first-time buyer, the home costs £450,000 or less and the account has been open for at least 12 months. The money goes to your conveyancer for completion, so it can’t usually pay the deposit due at exchange. The government has consulted on replacing the Lifetime ISA with a new First Time Buyer ISA, so check the current rules before relying on it.
What will my lender need for a gifted deposit?
Usually a signed gift letter confirming the money doesn’t need repaying and gives the giver no stake in the home, plus their ID and bank statements showing where the money came from. If family expect to be paid back, the lender treats it as a loan, which can reduce how much you can borrow.
Would interest on my savings shorten the timeline?
A little. In the £12,000 example, £36,000 earning 4% AER plus £750 a month reaches the goal in about 14 months instead of 16. The calculator leaves interest out, so treat its timeline as a cautious one.
When do I actually pay the deposit?
In England and Wales, part or all of it is usually paid to the seller’s solicitor at exchange of contracts, often 10% of the price, though 5% is commonly accepted if that’s your full deposit. The rest of your money is needed at completion. Have the cash ready in an account you can access before exchange.
Should spare savings go into the deposit or the reserve?
Put it into the deposit only if it moves you into a lower LTV band and the deal saving is worth it. On a £350,000 home, going from 10% to 15% takes another £17,500, more than double the £8,000 reserve in the example. Use the comparison table to see the full cash needed at each band.