First time buyer mortgage calculator

A first time buyer mortgage calculator is a tool that estimates how much you could borrow and what your monthly repayments might be. You enter your income, deposit amount, and the property price you have in mind, and the calculator returns a rough monthly figure based on current interest rates.

These calculators are useful for setting a realistic budget before you start viewing properties. They help you understand how changes to your deposit, the mortgage term, or the interest rate affect what you pay each month. For example, extending your mortgage from 25 to 30 years reduces monthly payments but increases the total interest you pay over the life of the loan.

Keep in mind that calculators provide estimates, not guaranteed offers. Lenders carry out detailed affordability checks that consider your spending habits, credit history, and existing financial commitments. For a clearer picture of what you can actually borrow, it helps to read our complete first time buyer guide and then speak with a qualified mortgage advisor who can assess your full circumstances.

Most UK lenders use an income multiple to calculate your maximum borrowing. The standard range is 4 to 4.5 times your gross annual salary, though some lenders offer up to 5.5 times for applicants in certain professions such as medicine, law, or accountancy.

If you are buying with a partner, lenders typically combine both incomes. A couple earning £30,000 and £25,000 respectively could borrow between £220,000 and £247,500 at standard multiples. You can explore this in more detail in our guide on how much you can borrow as a first time buyer.

Income multiples are only part of the picture. Lenders also run a stress test to check whether you could still afford repayments if interest rates rose by several percentage points. Outstanding debts, childcare costs, and regular financial commitments all reduce the amount you can borrow. If you have existing loans or credit card balances, paying these down before applying can increase your borrowing power significantly.

Four main factors determine what you pay each month: the amount you borrow, the interest rate, the mortgage term, and the repayment type.

Interest rate: Even small rate changes make a big difference over time. On a £200,000 mortgage over 25 years, the difference between a 4% and 5% rate is roughly £117 per month, or over £35,000 across the full term. Check the latest first time buyer mortgage rates to see what deals are currently available.

Mortgage term: A longer term means lower monthly payments but more total interest. A £180,000 mortgage at 4.5% costs around £1,000 per month over 25 years, compared to £867 over 30 years. The 30-year option saves £133 monthly but adds roughly £22,000 in total interest.

Repayment type: With a repayment mortgage, you pay off the capital and interest together, so the debt reduces each month. With an interest-only mortgage, you only pay the interest and need a plan to repay the capital at the end. Most first time buyers choose repayment mortgages because lenders rarely offer interest-only deals without a credible repayment strategy.

The minimum deposit for most first time buyer mortgages is 5% of the property price. On a £250,000 home, that means saving at least £12,500. However, putting down a larger deposit unlocks better interest rates and reduces your monthly repayments.

Lenders group mortgage deals by loan-to-value (LTV) ratio. A 10% deposit (90% LTV) typically offers rates around 0.3 to 0.5 percentage points lower than a 5% deposit (95% LTV). At 15% or 20% deposit, rates drop further. For a detailed breakdown of deposit requirements, see our guide on how much deposit first time buyers need.

If saving a full deposit feels out of reach, there are options to consider. A 95% mortgage lets you buy with just 5% down, while government schemes for first time buyers such as the Lifetime ISA or shared ownership can help bridge the gap. A guarantor mortgage is another route if a family member is willing to support your application.

Beyond your deposit and monthly repayments, buying your first home involves several additional costs that a basic calculator will not show you.

Solicitor or conveyancer fees: Legal work typically costs between £1,000 and £1,500 including disbursements such as local authority searches and land registry fees.

Survey costs: A basic mortgage valuation may be free with some lenders, but a homebuyer report (£250 to £600) or full structural survey (£500 to £1,200) gives you a much clearer picture of the property condition.

Stamp duty: First time buyers in England and Northern Ireland pay no stamp duty on properties up to £300,000. Between £300,001 and £500,000, you pay 5% on the portion above £300,000. For the latest thresholds, check our guide on first time buyer stamp duty.

Mortgage fees: Many competitive-rate mortgages charge an arrangement fee of £500 to £2,000. You can add this to your mortgage balance, but you will pay interest on it for the full term. Factor in broker fees, although when you get matched through Money Saving Advisors, there are no upfront advice fees to worry about.