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Recast Mortgage Calculator

See your new monthly payment after paying a lump sum and recasting your mortgage, how fast the fee pays for itself, and how a recast compares with keeping your old payment or refinancing.

Updated November 4, 2026. Free, no sign-up; everything runs in your browser and nothing you type is stored.

Recast mortgage calculator

Current loan balance ($)Interest rate (%)Months left on the loanLump sum toward principal ($)Lender's recast fee ($)

New monthly payment after the recast

–

–Current payment (principal + interest)

–Payment drop

–Months to earn back the fee

Recast vs extra principal vs refinance

–Interest left if you do nothing

–Interest left after a recast

–Interest left if you pay the lump sum and keep paying the old payment

–Paid off

Refinance rate (%)Refinance term (years)Refinance closing costs ($)

–Refinanced payment (no lump sum)

–Total interest + costs

What is a mortgage recast?

You pay a lump sum toward principal and the lender re-amortizes the smaller balance over the months left, at the same interest rate. The payoff date stays the same; the monthly payment drops. Lenders typically ask for a minimum lump sum (often $5,000 to $10,000) and charge a fee of a few hundred dollars. Conventional loans held by many servicers allow it; FHA, VA and USDA loans generally don't.

Example: $300,000 left at 6% with 300 months to go is $1,932.90 a month. Paying $50,000 and recasting gives $1,610.75, about $322 less each month; a $250 fee is earned back in under a month.

Recast, extra principal or refinance?

Recast: lower required payment, same rate and end date. Good when you want cash flow, or you sold a home and bought before it closed.
Lump sum without a recast: keep paying the old payment and the loan ends years earlier with the least interest, but the required payment doesn't fall.
Refinance: a new loan, new rate and new term. Worth it mainly when rates have dropped enough to cover closing costs, typically 2% to 5% of the loan.

Before sending a large lump sum, ask the servicer in writing whether they recast, the minimum amount, the fee and how long it takes.

Common questions

How much will my payment drop if I recast my mortgage?

Re-amortize the new balance over the remaining months at the same rate. $50,000 off a $300,000, 6% loan with 25 years left cuts the payment by about $322.

Does recasting save interest?

Yes, because the balance is smaller, but paying the lump sum and keeping the old payment saves more and pays the loan off sooner.

How much does a mortgage recast cost?

Usually a fee of about $150 to $500, plus a minimum lump sum the lender sets.

Can I recast an FHA or VA loan?

Generally no. Recasting is mostly offered on conventional loans; ask your servicer.

Is recasting better than refinancing?

If your current rate is already low, yes: you keep the rate and avoid closing costs. Refinancing makes sense when rates fall.

Sources

General information, not financial, tax or legal advice. Check important numbers with the official source before acting on them.