Mortgage Calculator
Editable market rates
Calculate your monthly mortgage payments, see the full amortization schedule, and check affordability. Works for both residential and buy-to-let mortgages.
Full UK monthly cost (P&I + council tax + insurance + service charge)
True out-of-pocket cost — not just P&I. For BTL, council tax is normally the tenant's liability during a tenancy (we show both with and without).
During a tenancy (tenant pays council tax)
£1,217/mo
During voids / owner-occupier
£1,416/mo
P&I£1,188
Council tax (Band D)£199
Buildings insurance£29
Service charge£0
Mortgage Details
£75,000
Loan-to-Value:
75% LTV
Market avg: 4%
Rates as of Apr 2026
25 years
UK fixes lock the rate for 2 / 5 years then revert to SVR. Trackers move with BoE base rate. Most BTL is on 5-year fixes for the longer stress-test exemption.
Monthly Payment
£1,188
Principal + Interest
Total Interest
£131,290
Over 25 years
Total to Repay
£356,290
Principal + Interest
LTV:75%
Loan:£225,000
Type:Residential
First 5 Years Breakdown
See how your payments are split between principal and interest
Year 1Balance: £219,651
Principal: £5,349Interest: £8,903
Year 2Balance: £214,084
Principal: £5,567Interest: £8,685
Year 3Balance: £208,290
Principal: £5,794Interest: £8,458
Year 4Balance: £202,261
Principal: £6,030Interest: £8,222
Year 5Balance: £195,985
Principal: £6,275Interest: £7,976
Recommendations
- WINLoan-to-value is 75% — within the 75% buy-to-let ceiling, so you keep access to the better-priced investor mortgages.
- TIPEven a small monthly overpayment shortens the term and cuts total interest — run the numbers in the overpayment calculator before you fix your deal.
Jargon: · · ·
LTV
LTV (Loan-to-Value)
Mortgage amount as a percentage of property value. A £150k loan on a £200k property = 75% LTV. BTL lenders typically cap at 75%; investor mortgages get cheaper as LTV drops.
ICR
ICR (Interest Coverage Ratio)
Lender's stress test: rent ÷ stressed mortgage interest. Most BTL lenders require ICR ≥ 1.25 at a stress rate of 5.5–7.5%. ICR < 1 means the rent cannot cover the stressed mortgage.
amortisation
Amortisation
How a repayment mortgage is paid down over time. Early payments are mostly interest; later ones are mostly capital. Overpaying cuts the balance directly, so less interest accrues and the term shortens.
overpayment
Overpayment
Paying more than your contractual monthly mortgage payment (or a one-off lump sum). It reduces the balance immediately, shortening the term and cutting total interest — but watch the 10% annual ERC allowance on fixed deals.
Monthly Payment Formula
M = P × [r(1+r)ⁿ] / [(1+r)ⁿ-1]
Where M = monthly payment, P = principal (loan amount), r = monthly interest rate (annual rate ÷ 12), and n = total number of payments (years × 12).