Mortgage Recast Calculator

Model one or many lump-sum payments, each on its own date, and compare recasting with simply paying them down. Results update as you type.

Loan details

Loan start date
First payment is due the month after the start date.

Lump-sum payments

Each payment goes to principal after that month's regular payment. The Recast column recalculates your monthly payment after every lump sum.

    Side-by-side comparison

    No extra paymentsRecastLump Sums

      Payment timeline (Recast)

        Remaining balance

        No extra Recast Lump Sums

        Amortization schedule

        How to read the results

        Recast: once you pay a lump sum toward principal, the lender recalculates your monthly payment from the new balance over the time left on the loan. Your rate and end date stay the same, but each month you pay less.

        Lump Sums: you pay the same lump sums and keep making your original payment. That clears the loan sooner and saves the most interest, but your monthly payment doesn't drop.

        This calculator assumes you recast after every lump sum. Servicers usually charge a fee for each recast. Many also set a minimum lump sum, often around $5,000 or more. Check the rules with your servicer.

        These figures are estimates for educational purposes only. They are not financial advice. Your actual loan terms, rounding, and servicer rules may produce different numbers.