Quick Answer: What Happens If I Pay $500 Extra on My Mortgage?
If you pay an extra $500 toward your mortgage principal every month on a $300,000 loan at 6.5% interest, you will save roughly $168,000 in interest and pay off your 30-year loan nearly 13 years early.
The Full Calculation: The Magic of Amortization
Mortgage interest is heavily front-loaded. In the first 10 years of a 30-year loan, the vast majority of your payment goes straight to the bank, not to building equity. When you pay extra toward the principal, you bypass this interest curve entirely.
Let's look at the math for a $300,000 loan on a 30-year fixed term at 6.5%:
- Standard Monthly P&I Payment: $1,896
- Total Interest Paid over 30 years: $382,633
Now, let's add an extra $500 per month specifically to the Principal:
- New Monthly P&I Payment: $2,396
- Time to Payoff: 17 years and 2 months (You shaved off 12 years and 10 months!)
- New Total Interest Paid: $214,085
- Total Savings: $168,548
What Affects This Number?
The amount of money you save by paying extra depends on a few variables:
- Your Interest Rate: The higher your interest rate, the more money you save by paying extra. If you have a 3% rate, paying extra yields a low return. If you have a 7% rate, the savings are massive.
- When You Start: Because interest is front-loaded, an extra $500 in Year 1 saves you drastically more money than an extra $500 in Year 20.
- Consistency: You don't have to pay extra every month. Even one extra payment a year (like a tax refund) can shave years off your loan.
How to Lower Your Payment (and Build Wealth)
Paying extra on your mortgage builds incredible wealth, but it does not lower your required monthly bill unless you recast the loan.
- Mortgage Recasting: If you drop a lump sum (e.g., $20,000) onto your principal, you can ask your lender to "recast" the loan. They will recalculate your monthly payment based on the new, lower balance without changing your interest rate or loan term. This lowers your monthly obligation permanently.
- Invest the Difference: If your mortgage rate is very low (e.g., 3%), mathematical purists suggest investing that $500 in the stock market instead, as historical returns usually beat a 3% interest savings.
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Try the Extra Payment Calculator →Frequently Asked Questions
How do I ensure the extra money goes to the principal?
When making an extra payment, you must explicitly instruct your lender to apply the funds to the 'Principal Balance'. Otherwise, they may simply apply it to next month's standard payment, which includes interest.
Are there penalties for paying off a mortgage early?
Most modern mortgages do not have prepayment penalties, but you should always check your loan closing documents or call your servicer to verify before making large extra payments.
Is it better to pay extra monthly or one lump sum yearly?
Mathematically, it is better to pay extra monthly. Because mortgage interest accrues monthly, lowering the principal balance sooner saves you more money over time.