Loan Recast Calculator
Pay down a chunk of the loan and have the lender re-figure your payment. See the new payment, the interest you save, and how it stacks up against just prepaying without the recast.
Ben / Reviewed Sep 27, 2026 / v2.0.0
Results
Showing the numbers you calculated- New payment
- $1,677.54
- $186.39 less than $1,863.93
- Interest saved
- $19,735.25
- $19,485.25 after the fee
- Balance after the lump sum
- $225,000.00
- Fee payback
- 2
- Months of lower payments to earn back the fee
- Interest left (no recast, no lump sum)
- $197,344.64
- Interest left after the recast
- $177,609.39
- Still ends 10/01/2046
- Skip the recast: interest saved
- $56,284.70
- Same lump sum, old payment — done 03/01/2043
- Skip the recast: time saved
- 3 years 7 months
Recast schedule
Swipe the table sideways to see all 6 columns.
| # | Date | Payment | Interest | Principal | Balance |
|---|---|---|---|---|---|
| 1 | 11/01/2026 | $1,677.54 | $1,218.75 | $458.79 | $224,541.21 |
| 2 | 12/01/2026 | $1,677.54 | $1,216.26 | $461.28 | $224,079.93 |
| 3 | 01/01/2027 | $1,677.54 | $1,213.77 | $463.77 | $223,616.16 |
| 4 | 02/01/2027 | $1,677.54 | $1,211.25 | $466.29 | $223,149.87 |
| 5 | 03/01/2027 | $1,677.54 | $1,208.73 | $468.81 | $222,681.06 |
| 6 | 04/01/2027 | $1,677.54 | $1,206.19 | $471.35 | $222,209.71 |
| 7 | 05/01/2027 | $1,677.54 | $1,203.64 | $473.90 | $221,735.81 |
| 8 | 06/01/2027 | $1,677.54 | $1,201.07 | $476.47 | $221,259.34 |
| 9 | 07/01/2027 | $1,677.54 | $1,198.49 | $479.05 | $220,780.29 |
| 10 | 08/01/2027 | $1,677.54 | $1,195.89 | $481.65 | $220,298.64 |
| 11 | 09/01/2027 | $1,677.54 | $1,193.28 | $484.26 | $219,814.38 |
| 12 | 10/01/2027 | $1,677.54 | $1,190.66 | $486.88 | $219,327.50 |
| 13 | 11/01/2027 | $1,677.54 | $1,188.02 | $489.52 | $218,837.98 |
| 14 | 12/01/2027 | $1,677.54 | $1,185.37 | $492.17 | $218,345.81 |
| 15 | 01/01/2028 | $1,677.54 | $1,182.71 | $494.83 | $217,850.98 |
| 16 | 02/01/2028 | $1,677.54 | $1,180.03 | $497.51 | $217,353.47 |
| 17 | 03/01/2028 | $1,677.54 | $1,177.33 | $500.21 | $216,853.26 |
| 18 | 04/01/2028 | $1,677.54 | $1,174.62 | $502.92 | $216,350.34 |
| 19 | 05/01/2028 | $1,677.54 | $1,171.90 | $505.64 | $215,844.70 |
| 20 | 06/01/2028 | $1,677.54 | $1,169.16 | $508.38 | $215,336.32 |
| 21 | 07/01/2028 | $1,677.54 | $1,166.41 | $511.13 | $214,825.19 |
| 22 | 08/01/2028 | $1,677.54 | $1,163.64 | $513.90 | $214,311.29 |
| 23 | 09/01/2028 | $1,677.54 | $1,160.85 | $516.69 | $213,794.60 |
| 24 | 10/01/2028 | $1,677.54 | $1,158.05 | $519.49 | $213,275.11 |
Without recasting (same lump sum, old payment)
Swipe the table sideways to see all 6 columns.
| # | Date | Payment | Interest | Principal | Balance |
|---|---|---|---|---|---|
| 1 | 11/01/2026 | $1,863.93 | $1,218.75 | $645.18 | $224,354.82 |
| 2 | 12/01/2026 | $1,863.93 | $1,215.26 | $648.67 | $223,706.15 |
| 3 | 01/01/2027 | $1,863.93 | $1,211.74 | $652.19 | $223,053.96 |
| 4 | 02/01/2027 | $1,863.93 | $1,208.21 | $655.72 | $222,398.24 |
| 5 | 03/01/2027 | $1,863.93 | $1,204.66 | $659.27 | $221,738.97 |
| 6 | 04/01/2027 | $1,863.93 | $1,201.09 | $662.84 | $221,076.13 |
| 7 | 05/01/2027 | $1,863.93 | $1,197.50 | $666.43 | $220,409.70 |
| 8 | 06/01/2027 | $1,863.93 | $1,193.89 | $670.04 | $219,739.66 |
| 9 | 07/01/2027 | $1,863.93 | $1,190.26 | $673.67 | $219,065.99 |
| 10 | 08/01/2027 | $1,863.93 | $1,186.61 | $677.32 | $218,388.67 |
| 11 | 09/01/2027 | $1,863.93 | $1,182.94 | $680.99 | $217,707.68 |
| 12 | 10/01/2027 | $1,863.93 | $1,179.25 | $684.68 | $217,023.00 |
Original schedule (no lump sum)
Swipe the table sideways to see all 6 columns.
| # | Date | Payment | Interest | Principal | Balance |
|---|---|---|---|---|---|
| 1 | 11/01/2026 | $1,863.93 | $1,354.17 | $509.76 | $249,490.24 |
| 2 | 12/01/2026 | $1,863.93 | $1,351.41 | $512.52 | $248,977.72 |
| 3 | 01/01/2027 | $1,863.93 | $1,348.63 | $515.30 | $248,462.42 |
| 4 | 02/01/2027 | $1,863.93 | $1,345.84 | $518.09 | $247,944.33 |
| 5 | 03/01/2027 | $1,863.93 | $1,343.03 | $520.90 | $247,423.43 |
| 6 | 04/01/2027 | $1,863.93 | $1,340.21 | $523.72 | $246,899.71 |
| 7 | 05/01/2027 | $1,863.93 | $1,337.37 | $526.56 | $246,373.15 |
| 8 | 06/01/2027 | $1,863.93 | $1,334.52 | $529.41 | $245,843.74 |
| 9 | 07/01/2027 | $1,863.93 | $1,331.65 | $532.28 | $245,311.46 |
| 10 | 08/01/2027 | $1,863.93 | $1,328.77 | $535.16 | $244,776.30 |
| 11 | 09/01/2027 | $1,863.93 | $1,325.87 | $538.06 | $244,238.24 |
| 12 | 10/01/2027 | $1,863.93 | $1,322.96 | $540.97 | $243,697.27 |
What this does
A recast (sometimes called re-amortization) is what happens when you pay a big chunk of principal and the lender recalculates your payment over the months you have left. Same rate, same end date, lower payment.
This shows the new payment and the interest it saves — and it runs the obvious alternative: pay the same lump sum but don't recast, keep your current payment, and finish the loan early.
How the math works
The recast payment is just the normal payment formula on the smaller balance:
new payment = PMT(rate ÷ 12, months left, balance − lump sum)
Both paths start from the same lower balance, so the interest savings come from the lump sum either way. The difference is what you do after:
- Recast: the payment drops and the loan still ends on the original date.
- No recast: the payment stays the same, so more of each payment goes to principal and the loan ends sooner — saving more interest.
A recast doesn't save you money on its own — the lump sum does. The recast just turns that lump sum into a lower payment instead of a shorter loan.
Check my math: a worked example
You owe $250,000 at 6.50% with 240 months left, paying $1,863.93 a month. You put $25,000 toward principal and recast (fee: $250).
- New balance: $225,000.00.
- New payment over the same 240 months: $1,677.54 — $186.39 less a month.
- Interest left: $197,344.64 before, $177,609.39 after — $19,735.25 saved ($19,485.25 after the fee).
- Skip the recast and keep paying $1,863.93: $141,059.94 of interest, paid off 03/01/2043 — 3 years 7 months early and $56,284.70 saved.
Recasting buys breathing room in the monthly budget; not recasting buys the most interest savings. Neither is wrong — it depends on whether you want the cash flow or the finish line.
These numbers come straight from the calculator using its example inputs — if the math ever changes, this example changes with it.
Mistakes I see a lot
- Assuming every loan can be recast. Many conventional mortgages allow it; FHA, VA, and most car loans don't. Ask the servicer.
- Thinking the recast itself saves interest. The lump sum does; the recast only changes how you feel it.
- Forgetting the minimum. Servicers often require $5,000–$10,000 (or more) toward principal before they'll recast.
- Paying a big fee to recast a small balance. Check how long the lower payment takes to cover the fee.
Questions people ask
- Recast or refinance?
- A recast keeps your rate and costs a small fee. A refinance can change the rate and term but comes with closing costs. If your rate is already good, a recast is the cheap way to lower the payment.
- Does a recast change my interest rate?
- No. Same rate, same maturity date — just a smaller balance and a smaller payment.
- Why does not recasting save more interest?
- Because you keep paying the higher payment on a smaller balance, the extra goes straight to principal every month and the loan is gone sooner.
- Does the spreadsheet recalculate?
- Yes. The original, recast, and no-recast schedules and the comparison all run off the Inputs sheet.
Assumptions and limits
- A recast keeps the rate and the remaining term; the lump sum lowers the balance and the lender re-figures the payment over the months you have left.
- The lump sum is paid just before the first payment at the new amount (the recast date). The recast fee is paid in cash — it isn't added to the loan.
- "Without recasting" means the same lump sum, but you keep making your current payment, so the loan finishes early instead of the payment dropping.
- If you enter your current payment, the current loan runs at that payment until it's paid off. Leave it blank for the payment that fits the remaining term.
- Fixed rate, monthly payments, lender-style rounding (payment and each month's interest to the cent). No escrow or prepayment penalties.
Disclaimer: Educational and planning use only. Results depend on what you enter and may not match your lender, your tax return, or professional accounting treatment. Informational content + opinions only — not tax/legal advice.