Loan repayment calculator
Compare scheduled payments, monthly overpayments and a one-time payment with a complete amortization table.
| Scenario | Payoff month | Total interest | Total paid |
|---|---|---|---|
| Scheduled only | 36 | $1,142.29 | $13,142.29 |
| Monthly extra only | 32 | $993.77 | $12,993.77 |
| Monthly + one-time extra | 30 | $926.87 | $12,926.87 |
The schedule below shows the combined extra-payment scenario. The final payment may be smaller or include a rounding adjustment.
View all 30 monthly rows
| Month | Opening | Interest | Payment | Extra included | Closing |
|---|---|---|---|---|---|
| 1 | $12,000.00 | $60.00 | $415.06 | $50.00 | $11,644.94 |
| 2 | $11,644.94 | $58.22 | $415.06 | $50.00 | $11,288.10 |
| 3 | $11,288.10 | $56.44 | $415.06 | $50.00 | $10,929.48 |
| 4 | $10,929.48 | $54.65 | $415.06 | $50.00 | $10,569.07 |
| 5 | $10,569.07 | $52.85 | $415.06 | $50.00 | $10,206.86 |
| 6 | $10,206.86 | $51.03 | $915.06 | $550.00 | $9,342.83 |
| 7 | $9,342.83 | $46.71 | $415.06 | $50.00 | $8,974.48 |
| 8 | $8,974.48 | $44.87 | $415.06 | $50.00 | $8,604.29 |
| 9 | $8,604.29 | $43.02 | $415.06 | $50.00 | $8,232.25 |
| 10 | $8,232.25 | $41.16 | $415.06 | $50.00 | $7,858.35 |
| 11 | $7,858.35 | $39.29 | $415.06 | $50.00 | $7,482.58 |
| 12 | $7,482.58 | $37.41 | $415.06 | $50.00 | $7,104.93 |
| 13 | $7,104.93 | $35.52 | $415.06 | $50.00 | $6,725.39 |
| 14 | $6,725.39 | $33.63 | $415.06 | $50.00 | $6,343.96 |
| 15 | $6,343.96 | $31.72 | $415.06 | $50.00 | $5,960.62 |
| 16 | $5,960.62 | $29.80 | $415.06 | $50.00 | $5,575.36 |
| 17 | $5,575.36 | $27.88 | $415.06 | $50.00 | $5,188.18 |
| 18 | $5,188.18 | $25.94 | $415.06 | $50.00 | $4,799.06 |
| 19 | $4,799.06 | $24.00 | $415.06 | $50.00 | $4,408.00 |
| 20 | $4,408.00 | $22.04 | $415.06 | $50.00 | $4,014.98 |
| 21 | $4,014.98 | $20.07 | $415.06 | $50.00 | $3,619.99 |
| 22 | $3,619.99 | $18.10 | $415.06 | $50.00 | $3,223.03 |
| 23 | $3,223.03 | $16.12 | $415.06 | $50.00 | $2,824.09 |
| 24 | $2,824.09 | $14.12 | $415.06 | $50.00 | $2,423.15 |
| 25 | $2,423.15 | $12.12 | $415.06 | $50.00 | $2,020.21 |
| 26 | $2,020.21 | $10.10 | $415.06 | $50.00 | $1,615.25 |
| 27 | $1,615.25 | $8.08 | $415.06 | $50.00 | $1,208.27 |
| 28 | $1,208.27 | $6.04 | $415.06 | $50.00 | $799.25 |
| 29 | $799.25 | $4.00 | $415.06 | $50.00 | $388.19 |
| 30 | $388.19 | $1.94 | $390.13 | $25.07 | $0.00 |
Illustrative calculations, not financial advice or a lender quote. See the assumptions and limitations below.
What this calculation assumes
A fixed-rate loan with monthly interest on the outstanding balance. Extra payments reduce principal after the scheduled payment. The scheduled payment is not recast after an overpayment.
The formula
Monthly payment = P × r ÷ [1 − (1 + r)⁻ⁿ]. At 0%: P ÷ n. Each month: interest = opening balance × r; principal repaid = total payment − interest.
P is the starting balance, n is the remaining monthly term, and r is annual interest percentage ÷ 1,200. Use the contract interest rate, not a fee-inclusive APR.
Timing and rounding
Scheduled payment and each month’s interest are rounded to cents. The final payment is adjusted to clear the remaining balance, including a small rounding residual. Extra payments are capped at the outstanding amount. A one-time payment after payoff is never charged.
Where the model stops
Excludes origination fees, late charges, prepayment penalties, taxes and insurance. Daily-interest loans, revolving credit cards, variable rates and irregular payment dates need a different model. Ask your lender how an overpayment is allocated.
Questions about this tool
Is this my exact lender payoff quote?
No. Your contract can use a daily accrual method, different rounding, fees or payment allocation rules. Use this table to understand the model and compare it with your lender’s statement.
Why can the last payment be different?
The regular payment is rounded to cents. We adjust the last payment to avoid leaving a few cents unpaid or charging more than the remaining balance.
Check the method
See our calculation and testing notes, or report a reproducible discrepancy.
Conceptual reference: CFPB: How paying down a mortgage works. This source is not an endorsement of SimpleFinCalc or a validation of its outputs.