Extra Mortgage Payments Calculator

Discover how much interest and time you can save by making extra principal payments on your mortgage.

$
%
yrs
$
Interest Saved
$91,847
Pay off 6 yrs 5 mos earlier
Current Payoff Date
March 2054
New Payoff Date
October 2047
Base Monthly Payment
$1,857
New Monthly Payment
$2,057
Total Interest (no extra)
$343,964
Total Interest (with extra)
$252,117

How to Use This Extra Payments Calculator

Enter your Current Balance, Interest Rate, and Years Remaining to establish your baseline. Then add your Extra Monthly Payment to immediately see your new payoff date and interest savings.

Click More options to add an annual lump sum (great for tax refunds or bonuses) and a one-time immediate principal payment. The calculator combines all three types of extra payments for a comprehensive view of your accelerated payoff.

Getting the Most Accurate Results

Use your remaining balance from your latest mortgage statement (not the original loan amount). Use your years remaining, not your original term. This gives you the most accurate payoff projection based on your current situation.

How Extra Payments Reduce Interest

Monthly Interest = Remaining Balance × (Annual Rate ÷ 12)

Every extra dollar paid reduces the balance,
which reduces next month's interest charge,
which means more of the regular payment goes to principal.

Compounding effect: each extra payment accelerates
all future principal reduction.

On a $280,000 loan at 6.75%, the first month's interest is $1,575. After an extra $200 payment, the next month's interest is $1,573 — saving $2. Small individually, but this compounds every month for 20+ years, producing dramatic total savings.

Example: The Power of $200 Extra Per Month

Scenario: $280,000 at 6.75%, 28 Years Remaining

Base Monthly Payment$1,816
Extra Monthly Payment$200
New Monthly Total$2,016
Original Payoff28 years
New Payoff~22 years
Time Saved~6 years
Original Total Interest$353,000
New Total Interest$282,000
Interest Saved~$71,000

An extra $200/month — about $7/day — saves $71,000 in interest and 6 years of payments. The total extra cost is 22 years × $200 × 12 = $52,800, but the savings more than offset this through eliminated interest.

Frequently Asked Questions

On a $280,000 loan at 6.75%, extra monthly payments save: $100 extra = ~$40,000 saved, 3.5 years early. $200 extra = ~$71,000 saved, 6 years early. $500 extra = ~$120,000 saved, 11 years early. Use the calculator for your exact situation.
Compare your mortgage rate to expected investment returns. Extra mortgage payments deliver a guaranteed, risk-free return equal to your interest rate. If your mortgage is 7% and you expect 10% investment returns, investing may win mathematically — but guaranteed savings have value that numbers don't capture. A common approach: fund your 401k match first, then split extras between mortgage paydown and investments.
Specify "apply to principal" when making the payment — in writing, by phone, or via your lender's online portal. Some lenders apply extra funds to future scheduled payments instead, which doesn't accelerate your payoff. Always verify on your next statement that your balance decreased by the expected amount.
Most conventional mortgages originated after 2014 have no prepayment penalty under CFPB rules. Older loans or specialty products may have penalties of 2–4% of the prepaid amount during the first 3–5 years. Check your original loan documents under "Prepayment" before making large lump-sum payments.
Extra payments are most powerful early in the loan when your balance is highest and interest charges are greatest. However, any extra payment at any time reduces your principal and future interest. If you have a windfall late in your loan, the dollar savings are smaller but still worthwhile since every month eliminated is one less payment to make.

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