Mortgage payment planning

Mortgage Recast Calculator

Estimate a lower principal-and-interest payment after a lump-sum principal reduction, then compare it with keeping the current payment and finishing the mortgage sooner.

Use the unpaid principal balance, not the original loan amount.
The estimate assumes the rate stays unchanged after the recast.
The recast payment uses the remaining term entered here.
Enter the amount applied directly to principal before the payment is recalculated.
This affects the cash used now, but it does not reduce the loan balance.

Results will appear after valid values are entered.

Estimated recast payment

The calculator applies the lump sum to principal, then amortizes the lower balance across the same remaining term at the same fixed rate.

Current estimated payment — Principal and interest only
Balance after lump sum — Current balance minus principal payment
Estimated recast payment — Same rate and remaining term
Monthly payment reduction — Annual principal-and-interest reduction

Lower payment or faster payoff

Both strategies begin with the same lump-sum principal payment. Recasting lowers the required payment. Keeping the original payment applies the monthly difference to principal and can finish the loan sooner.

Comparison of the current schedule and two lump-sum strategies
Scenario Monthly P&I Estimated payoff Remaining interest Cash used now
Enter valid values to build the comparison.
Interest saved by recasting — Compared with making no lump-sum payment
Interest saved by keeping payment — Compared with making no lump-sum payment
Extra interest from lower payment — Recast interest minus keep-payment interest
Time saved by keeping payment — Estimated accelerated payoff

What the estimate leaves out

Recast eligibility, minimum principal reductions, fees, processing dates, and loan restrictions vary. The estimate excludes escrow, property taxes, insurance, mortgage insurance, HOA dues, adjustable rates, deferred balances, and interest-only features.

Confirm the actual payment, balance, remaining term, and recast terms with the mortgage servicer before sending a large payment.

Related guide

Compare a lower payment with a faster payoff

Learn what a recast changes, what stays the same, which questions to ask the servicer, and when keeping the current payment may be more useful.

Should You Recast Your Mortgage?

Work through payment, interest, liquidity, and timing examples before committing a lump sum to home equity.

Read the mortgage recast guide →

For educational purposes only. Results are estimates. Review the Calculator Methodology for shared assumptions, rounding, payoff timing, and privacy-conscious analytics details.