Most UK mortgage deals only fix your rate for two or five years. Here’s what your payment looks like while that lasts, and what changes after.
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Get your monthly payment, full amortization schedule, and see how extra payments cut your payoff time. Calculated in your browser.
| Year | Principal paid | Interest paid | Remaining balance |
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How loan EMI and amortization are calculated
Monthly payment (EMI) = P × r × (1+r)n ÷ ((1+r)n − 1), where P is the loan amount, r is the monthly interest rate, and n is the number of monthly payments. Each payment splits between interest (on the remaining balance) and principal — early payments are mostly interest, later ones mostly principal. Any extra monthly payment goes entirely to principal, which reduces future interest and shortens the loan.
Loan calculator FAQ
How is a loan EMI calculated?
EMI = P × r × (1+r)^n ÷ ((1+r)^n − 1), where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments. This gives a fixed payment that covers both interest and principal over the loan term.
What is the difference between a loan calculator and a mortgage calculator?
They use the same amortization math — a mortgage is simply a loan secured against property. This calculator works for both personal loans, auto loans and home mortgages; just enter the loan amount, rate and term.
How much interest can I save by paying extra each month?
Extra payments go straight toward principal, which reduces the interest charged on every future payment and shortens the loan term. Even a modest extra amount can save thousands in interest and cut years off a mortgage — see the comparison above for your exact numbers.
Does this calculator include a full amortization schedule?
Yes. Scroll to the year-by-year breakdown table to see principal paid, interest paid and remaining balance for every year of the loan.
What is an amortization schedule?
An amortization schedule shows how each payment splits between interest and principal over the life of a loan. Early payments are mostly interest; later payments are mostly principal, even though the total payment stays the same.
Is this loan calculator free and private?
Yes. It runs entirely in your browser — no amounts are uploaded, stored or shared, and there is no sign-up.
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Why “25-year mortgage” doesn’t mean 25 years of the same rate
Almost nobody in the UK takes a single fixed rate for the full term the way it commonly works in the US. Instead, you fix for an initial period, usually two or five years, then the mortgage reverts to your lender’s standard variable rate (SVR) unless you remortgage onto a new deal. This calculator assumes one fixed rate for the whole term, which is exactly right for working out your payment during the initial fixed period. When your deal ends, come back and re-run it with your new rate to see the updated payment.
Loan-to-value and why your rate depends on your deposit
UK lenders price mortgages heavily around loan-to-value (LTV), the size of your mortgage as a percentage of the property’s value. A 10% deposit puts you at 90% LTV; a 40% deposit puts you at 60% LTV, and typically gets you noticeably better rates. If you’re comparing deals, run this calculator with a couple of different rates to see how much a lower LTV band is actually worth to you in monthly terms, not just as a headline percentage.
Overpayments: check your allowance first
Most fixed-rate UK mortgages let you overpay up to 10% of the outstanding balance per year without an early repayment charge, though the exact allowance varies by lender and deal. Within that limit, the extra-payment field above works exactly as intended, showing how much time and interest a regular overpayment saves. Overpay beyond your allowance during a fixed period and you may face a penalty that wipes out the benefit, so check your mortgage offer document before entering a number larger than your allowance covers.
What this doesn’t include
Stamp Duty Land Tax, a one-off tax due on completion rather than part of your monthly payment, isn’t part of this calculation, and neither are buildings insurance or any product/arrangement fee your lender charges upfront. This tool covers the mortgage payment itself: principal and interest, month by month, for the rate and term you enter.