Mortgage & real estate

Mortgage Acceleration Calculator

Enter your loan, rate, term and an extra monthly amount to see how much faster the mortgage is paid off.

  • Free
  • No sign-up
  • Updated for 2026

Loan & extra payment

$
%
yr
$

on top of the normal payment

Enter the loan, rate, term and extra payment to see the accelerated payoff.

Worked example

With these example inputs:

  • Loan amount$300,000
  • Interest rate6.5%
  • Loan term30 yr
  • Extra monthly payment$200

Total monthly payment: $2,096

  • Loan amount$300,000
  • Total interest$279,185
  • Total of payments$579,185
  • Payoff time23 yr 1 mo
  • Interest saved$103,449
  • Time saved6 yr 11 mo

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What mortgage acceleration means

Mortgage acceleration means paying a loan off early. You add a little to each payment. This tool shows the new total monthly payment. You enter the loan amount, rate and term. You also add an extra monthly payment. The tool then shows the payoff and savings.

Why extra payments help

Most of an early payment goes to interest. Extra money instead cuts the balance directly. A smaller balance means less interest each month. That speeds up every payment after it. Small extras can save years and a lot of interest. The earlier you start, the bigger the gain.

How to use this calculator

Enter four values. Put in the loan amount and the interest rate. Add the loan term in years. Then add an extra monthly payment. The tool shows the total payment and the time saved.

How it is calculated

The tool builds the loan's schedule month by month. It adds your extra to each normal payment. Total payment = normal payment + extra. Each month the larger payment cuts the balance faster. The loan then ends sooner than its term.

A worked example

Take a loan of three hundred thousand at six point five percent. The term is thirty years. Add an extra of two hundred each month. The total monthly payment becomes about two thousand ninety six. The loan clears in about two hundred seventy seven months.

Reading the result

The headline is the new total monthly payment. Below it you see the time saved. Here the extra saves about eighty three months. It also cuts the interest by a large sum. That is the reward for paying a little more.

Where the savings come from

Every extra unit goes straight at the balance. A lower balance earns the lender less interest. Less interest means more of each payment cuts principal. The effect builds on itself over time. That is why early extras matter most. Time turns a small extra into big savings.

Common mistakes to avoid

One slip is forgetting the extra is per month. Another is ignoring fees for early payoff. Some lenders charge a prepayment penalty. Check your terms before you commit. Also keep a cash cushion for emergencies.

The limits of this tool

This calculator assumes a fixed rate. It does not model a rate that changes. It ignores taxes, insurance and fees. It also assumes every extra is paid on time. Use it as a guide, not a promise. Your real schedule may differ slightly.

Making acceleration work

Set the extra at a level you can hold. A steady small amount beats a rare large one. Pay it every month for full effect. Confirm the extra goes to principal. Then watch the term shrink over time.

A final tip

Test a few extra amounts to compare. A larger extra shortens the loan more. Weigh it against other uses for the cash. A clear payoff plan keeps you on track.

Frequently asked questions

How does paying extra accelerate a mortgage?

Every extra dollar goes straight to principal, so the balance falls faster and less interest accrues. Even a modest extra amount each month can cut years off a 30-year loan.

Is it better to pay extra or invest?

It depends on your mortgage rate versus expected investment returns and your appetite for risk. Paying down the loan is a guaranteed, tax-free return equal to your interest rate.