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monthly payment
A repayment mortgage's monthly cost comes from the standard annuity formula on the loan (property value minus deposit), the monthly rate and the term. Loan-to-value — the loan as a share of the property price — decides the rates lenders offer: bands typically improve at 90%, 80% and 75%, so a slightly larger deposit that crosses a band can cut the rate on the whole loan. Interest-only payments are lower but the entire loan remains owed at term end.
The five-year balance rows show amortisation's uncomfortable start: early payments are mostly interest, so the balance falls slowly at first and accelerates later. This is why overpayments early in the term save disproportionate interest, why the total-interest figure can approach the loan itself on long terms, and why extending a term to trim the monthly payment costs so much across the whole mortgage. Rate changes hit hardest early too, when the balance is largest.