How this calculator works
Your regular payment is worked out from the balance, rate and years left. The calculator then runs two payoffs: one at the regular payment and one with the lump sum taken off the balance up front and the extra added each month. The difference is the time and interest saved.
Worked example
With the example values below: Paid off, 5 yrs sooner (interest saved $66,894). Change any number above to run your own.
What you enter
| Input | Example |
|---|---|
| Remaining balance | $280,000 |
| Interest rate | 6.5% |
| Years remaining | 25 yrs |
| Extra each month | $200 |
| One-time payment now | $0 |
Ways to pay off a mortgage early
The calculator handles extra monthly payments and a one-time lump sum together, so you can test combinations.
- Extra monthly principal: add a fixed amount to every payment.
- Biweekly payments: half the payment every two weeks, which adds one extra payment a year.
- Lump sums: put bonuses, tax refunds or windfalls toward principal.
- Round up: pay $2,100 instead of $2,047, for example.
- Refinance to a shorter term, such as 15 years, if the higher payment fits.
How much early payoff saves
On a $280,000 balance at 6.5% with 25 years left, the regular payment is about $1,891. Adding $200 a month pays the loan off about five years early and saves roughly $67,000 of interest. A one-time $10,000 payment now saves about $37,000 of interest and cuts off around two years.
Savings are largest early in the loan, when the balance is highest and most of each payment is interest.
Pay off the mortgage or invest?
Extra mortgage payments earn a guaranteed return equal to your interest rate. Investing may earn more over long periods but with risk. Most people should first capture any employer 401(k) match, keep an emergency fund and pay off higher-rate debts.
After that it's a judgement call: with a mortgage rate of 6% or more, paying it down is competitive with expected investment returns; with a rate of 3% to 4%, investing usually comes out ahead on paper. Many people split the difference. The investment calculator can show the other side of the comparison.
Practical tips
Tell your servicer to apply extra money to principal, and check your statement to confirm it. Standard mortgages don't have prepayment penalties, but check your loan documents. If you want a lower required payment after a big lump sum, ask about a recast, which re-amortizes the loan over the remaining term for a small fee. Paying down principal also helps you cancel PMI sooner.
Frequently asked questions
How can I pay off my mortgage faster?
Add extra principal to each payment, switch to biweekly payments, put lump sums toward principal or refinance into a shorter term. Even $100 to $200 extra a month can cut years off a 30-year loan.
What happens if I pay an extra $500 a month on my mortgage?
On a $280,000 balance at 6.5% with 25 years left, an extra $500 a month pays the loan off in about 15½ years instead of 25 and saves roughly $122,000 in interest.
Is it better to pay off a mortgage early or invest?
Paying it down earns a guaranteed return equal to your rate. Investing may earn more over time but with risk. Higher-rate mortgages favor paying down; low-rate mortgages favor investing once you have an emergency fund and retirement match.
Does paying extra principal lower my monthly payment?
Not on a standard mortgage. It shortens the loan instead. A lender recast after a large lump sum can lower the required payment.
Do biweekly mortgage payments really help?
Yes. Paying half your payment every two weeks adds up to 26 half-payments, or 13 full payments, a year. On a 30-year loan that typically cuts four to six years off. Avoid third-party services that charge fees for this.
Grow what this calculator projects.
TruthSayer AI sends quantitative stock signals across valuations, earnings and dark-pool activity, each one traded in its own funded account first.
Estimates for planning only, not financial, tax or legal advice. Tax tools use 2026 federal figures (brackets, $16,100 / $32,200 standard deduction, $19,000 gift exclusion, $15M lifetime exemption). Rates shown as defaults are examples; replace them with quotes you actually receive.