What Happens When You Make Extra Loan Payments?

How extra payments work

Each extra dollar applied to principal directly reduces the balance. Future months calculate interest on a smaller balance — so the savings compound. Unlike a regular payment (where most early dollars go to interest), an extra payment is 100% principal.

Real examples

$300K mortgage at 6.5%, 30-year

• No extra payments: paid off in 30 years, total interest ~$382,500.
• +$100/month: paid off in ~26.8 years, save ~$48,000 interest.
• +$200/month: paid off in ~24.3 years, save ~$81,000 interest.
• +$500/month: paid off in ~19.5 years, save ~$143,000 interest.

$25K car loan at 8%, 5-year

• No extra: paid off in 5 years, total interest ~$5,415.
• +$50/month: paid off in 4.2 years, save ~$830.
• +$100/month: paid off in 3.7 years, save ~$1,400.

When extra payments make the most sense

• High-interest debt (anything above ~7%) — guaranteed return equal to the rate.
• Loans early in their term — interest portion is largest, so savings are biggest.
• When you have no other higher-priority goals (no debt, full emergency fund, getting employer 401(k) match).

When NOT to make extra payments

• If your interest rate is below ~5% and you could invest at 7%+ instead.
• If you don't have an emergency fund yet.
• If you're missing the 401(k) employer match to do it.
• If your loan has a prepayment penalty (rare, but check).

How to actually do it

1. Confirm your lender accepts extra principal payments without penalty.
2. When paying online, look for a separate 'principal-only' field — or call to ensure extra is applied to principal, not next month's payment.
3. Automate a monthly extra amount instead of waiting for windfalls.
4. Apply tax refunds, bonuses, and side-gig income directly to principal.

Use the calculator

Frequently Asked Questions