EconReads
Donate

Real Estate & Housing

How Mortgages Work

The basic mechanics of a mortgage loan, and why so much of an early payment goes toward interest rather than the loan balance.

A mortgage is a loan used to buy property, where the property itself serves as collateral - if payments stop, the lender can ultimately take possession of the property through foreclosure. Understanding its basic mechanics makes the much larger numbers involved in buying a home considerably less intimidating.

Principal, interest, and the loan term

The principal is the actual amount borrowed - the home’s price minus the down payment. The loan term is the length of time over which the loan is scheduled to be repaid, commonly 15 or 30 years. Every monthly payment is split between principal (which reduces what’s owed) and interest (the cost of borrowing), based on the same interest-rate mechanics covered in the credit and debt module.

Amortization: why early payments feel unfair

Amortization is the schedule by which a loan’s payments shift over time from being mostly interest to being mostly principal, even though the total payment amount stays the same throughout the loan term. Early in a mortgage, the outstanding balance is largest, so the interest owed on it each month is largest too - meaning a smaller share of an early payment actually reduces the principal.

Seeing amortization in a real payment

On a 30-year mortgage, a payment made in year one might be roughly 70% interest and 30% principal, while a payment made in year twenty-five on the same loan might be roughly 90% principal and 10% interest. The total payment hasn't changed - what's changed is the shrinking balance the interest is calculated against, since more of the loan has already been paid down by that point.

Why loan term changes the total cost dramatically

A 15-year mortgage carries meaningfully higher monthly payments than a 30-year mortgage on the same principal, but pays off in half the time and typically at a lower interest rate - resulting in dramatically less total interest paid over the life of the loan.

Comparing mortgages by monthly payment alone

A lower monthly payment on a longer loan term can look more attractive in the moment, but it often means paying substantially more in total interest over the full life of the loan. The monthly payment matters for what's actually affordable today, but the total cost of the loan is the number that matters for the full financial picture.

Why this connects to the rest of this module

Before a mortgage’s monthly payments even begin, there’s the upfront cost of actually closing the purchase - covered directly in the next lesson on down payments and closing costs.

Key takeaways
  • A mortgage uses the property itself as collateral for the loan used to buy it.
  • Every payment splits between principal (reducing debt) and interest (the cost of borrowing).
  • Amortization means early payments are mostly interest; later payments are mostly principal.
  • A shorter loan term means higher monthly payments but dramatically less total interest paid.
4 min read

No recording for this one yet - EconReader can read it aloud for you.

Welcome to EconReads

This site is made for visually impaired learners, so our read-aloud reader is already switched on to help you explore hands-free.

You're in control - turn it off any time using the Reader button at the top of the page.

EconReader Ready