One of the most common questions from first-time buyers is how much deposit they actually need. The honest answer is: as much as you can reasonably save, without delaying your purchase so long that house prices outpace your savings.
Compare deposit scenarios
Use our mortgage calculator with the deposit slider to see the difference instantly.
Try the calculator →5% deposit — the minimum
Gets you onto the property ladder with the smallest upfront cost — but fewer lenders, higher rates, and more total interest paid. On a £250,000 property at ~5.2% over 25 years, total interest is approximately £208,000.
10% deposit — the sweet spot
Moving from 5% to 10% makes a significant difference. At ~4.6%, monthly payments drop to around £1,340 on the same property — saving £147/month and tens of thousands over the full term.
20–25% deposit — best deals
At 75–80% LTV you unlock the most competitive rates. A 25% deposit on £250,000 could secure rates as low as 3.8–4.0%, with monthly payments around £1,164.
💡 The real question is how long it takes to save the larger deposit vs the extra cost of going in earlier with less. If house prices rise faster than you can save, waiting for a bigger deposit can leave you worse off.