Should I Pay Off My Mortgage Early?

A $300,000 mortgage at 6.5% over 30 years costs $1,896 a month and $382,637 in interest — more than the house.

Overpaying changes that dramatically, because every extra dollar goes straight to principal and stops accruing interest for the remaining term.

What each extra $100 buys

Extra per month	Cleared in	Interest paid	Interest saved
$0	30.1 years	$382,637	—
+$100	26.0 years	$321,641	$60,996
+$200	23.1 years	$279,186	$103,450
+$300	20.8 years	$247,519	$135,117
+$500	17.5 years	$202,875	$179,761

The first $100 is worth more than any subsequent $100 — it saves $61,000, while the fifth saves $45,000. Overpaying has diminishing returns, but they diminish slowly.

Model your own mortgage with the mortgage calculator, or see the payment-by-payment split in the amortization calculator.

Why early payments are worth so much more

In year one of a 30-year mortgage at 6.5%, about $1,625 of your $1,896 payment is interest. Only $271 touches the principal.

An extra $200 in that first month does not save you $200. It removes $200 of principal that would otherwise have accrued 6.5% compounding for the next 29 years — which is why the saving is roughly six times the payment.

The same $200 applied in year 25 saves almost nothing, because there is barely any interest left to avoid. Overpaying is a young-mortgage strategy.

When paying early is the wrong move

When the mortgage rate is low. A 3% mortgage is cheap debt. Paying it down returns a guaranteed 3% — and any other use of the money that beats 3% is better. A 2020-era mortgage is an asset, not a burden.

When you have any higher-rate debt. A credit card at 24% makes this an easy ranking. Paying down the card returns 24% guaranteed; paying down the mortgage returns 6.5%. Clear the card first, every time. See what APR actually costs you.

When you have no emergency fund. Money paid into a mortgage is extremely hard to get back out. You cannot un-overpay when the car breaks; you would be borrowing against the house at a worse rate to undo it. Build the cash buffer first.

When you are not taking the full 401(k) match. An employer match is an immediate 50–100% return. Nothing about a mortgage competes with that.

The comparison that decides it

The real question is not "is saving $103,450 good" — it obviously is. It is what else that $200 a month could do.

At a 7% average return, $200 a month invested over the same 23 years grows to roughly $140,000. That beats the $103,450 of interest saved — on average, over a long period, with risk, and with the money still accessible.

The mortgage overpayment is guaranteed, unleveraged, and locked in the house. The investment is larger on average and could be worth much less on the day you need it.

There is no universally right answer, and anyone who gives you one without asking your rate is not doing the arithmetic. Above roughly 6%, overpaying is genuinely competitive with investing. Below 4%, it usually is not.

The practical points nobody mentions

• Say what the extra payment is for. Many lenders apply overpayments to the next month's payment by default rather than the principal, which achieves nothing. It usually has to be specified.
• Check for early repayment charges, common on UK fixed-rate deals and some US loans.
• Overpay monthly rather than annually. The interest is charged monthly, so earlier is better.

If you are weighing a shorter term instead, 15-year vs 30-year mortgage compares the two directly.