Mortgage basics — mortgage guides

How a mortgage actually works, what the calculator is doing behind the monthly figure, and the vocabulary you need before comparing two offers.

Mortgage basics Rates and costs Affordability and deposit Mortgage types Refinancing and overpaying

3 guides

Index cards laid out in a row, one term to a card

Mortgage Terms Explained: The Words on Every Offer

APR, LTV, DTI, amortisation, early repayment charge, porting — the vocabulary you need before comparing two offers, with what each one actually costs you.

Mortgage basics 8 min read

A front door and a set of keys — the loan is only the way in

How a Mortgage Actually Works, Start to Finish

What you are agreeing to when you take a mortgage: the security, the stages of the process, and the points where the deal can still change.

Mortgage basics 9 min read

A calculator and a repayment table on a kitchen table, the arithmetic behind one monthly number

How a Mortgage Calculator Works: The Formula, Shown

One equation produces the monthly payment, and everything else follows from running it month by month. Here is the arithmetic, and what most calculators leave out.

Mortgage basics 8 min read

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Last updated 2026-08-05 by mortgagecalculator.siten.co · About us

Written in house

Every guide is researched and written by our editorial team, not rewritten from a lender’s marketing page.

Reviewed on a schedule

Each guide carries the date of its last review, and we publish the date even when nothing changed.

The arithmetic is shown

Where a figure comes from a formula we print the formula, so you can check it rather than trust it.

Twelve languages, twelve markets

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