Estimate how extra payments may change your home equity loan payoff date, interest saved, and savings after an early payoff fee.
Table of contents
How to use our Home Equity Loan Early Payoff Calculator
- Enter your Current loan balance, Annual interest rate, Current monthly payment, Extra paid each month, and Start date.
- Open Advanced options if you want to test a One-time extra payment, choose the One-time payment month, or subtract an Early payoff fee.
- Select Calculate to compare your regular payment plan with your extra-payment plan.
- Read Interest saved after early payoff fee first, then check Months paid off sooner and Interest saved before fees to see whether the fee changes the decision.
- Sanity-check the answer: if Total interest with your plan is higher than Total interest with regular payments, or the Calculation note says the payment is too low, review your balance, rate, and payment entries.
Definitions
Home equity loan: A loan that lets you borrow against home equity and pay it back over time, usually with fixed payments [1].
Current loan balance: The amount you still owe today.
Annual interest rate: The yearly interest rate used to estimate monthly interest.
Current monthly payment: Your regular monthly principal and interest payment before any extra amount.
Extra paid each month: The added amount you plan to pay every month on top of the regular payment.
One-time payment month: The payment number when the one-time extra payment is added. Month 1 is the first payment after the Start date.
Early payoff fee: A fee you may owe for paying off the loan early. The calculator subtracts it from gross interest savings.
Amortization: The month-by-month process where each payment first covers interest and the rest reduces the loan balance.
Common mistakes and quick fixes
Mistake: Using the original loan amount for Current loan balance.
Fix: Enter the amount still owed today in Current loan balance.
Mistake: Typing the monthly rate in Annual interest rate.
Fix: Enter the yearly loan rate in Annual interest rate, such as 8 for 8% per year.
Mistake: Including taxes, insurance, or optional charges in Current monthly payment.
Fix: Use the regular principal and interest part of Current monthly payment only.
Mistake: Adding the same dollars to both Extra paid each month and One-time extra payment.
Fix: Put recurring extra dollars in Extra paid each month and a single future lump sum in One-time extra payment.
Mistake: Setting One-time payment month after the loan would already be paid off.
Fix: Use Payoff month with your plan to choose a One-time payment month that happens before payoff.
Mistake: Ignoring Early payoff fee when judging savings.
Fix: Compare Interest saved after early payoff fee with Interest saved before fees before deciding.
Limitations & Key Assumptions / Boundary Conditions
- The estimate uses monthly compounding and one payment per month. A lender may use daily interest, different posting dates, or payoff statement rules.
- The Start date is used only to estimate Estimated payoff date with your plan. The first payment is treated as one month after the Start date.
- The calculator does not include taxes, insurance, late fees, escrow items, or optional charges in Current monthly payment.
- Only one future One-time extra payment is modeled. Multiple lump-sum payments or changing monthly payments over time are outside this estimate.
- Early payoff fee is user-entered. If your lender has a prepayment penalty formula, payoff quote fee, recording fee, or release fee, enter the expected total fee.
- If Current monthly payment does not cover the first month's interest, the loan balance will not go down and the calculator blocks the result.
- Results are estimates for planning. Use your lender's payoff quote before making a final payoff decision.
Methodology
How the monthly rate is found
The calculator turns the Annual interest rate into a monthly rate because the payment loop runs one month at a time.
monthly_rate = annual_rate_percent / 100 / 12
If the Annual interest rate is 0, the monthly rate is 0 and no interest is added.
How each month is calculated
For each payment month, the calculator adds interest to the starting balance, adds the regular payment and any extra payments scheduled for that month, then caps the payment so it cannot overpay the loan.
interest_m = balance_start_m * monthly_rate
scheduled_payment_m = current_monthly_payment + extra_monthly_payment + one_time_extra_payment_if_m_matches
actual_payment_m = min(scheduled_payment_m, balance_start_m + interest_m)
balance_end_m = balance_start_m + interest_m - actual_payment_m
The regular plan uses Current monthly payment only. The extra-payment plan includes Extra paid each month and the One-time extra payment only when the payment month matches One-time payment month. The loop stops when the balance reaches zero, or at 1200 months as a safety limit.
How savings are compared
Total interest is found from the total paid in the loop minus the starting Current loan balance.
total_interest = total_actual_payments - starting_loan_balance
Gross interest savings compares the regular plan with the extra-payment plan before any fee.
gross_interest_saved = regular_total_interest - plan_total_interest
Net savings subtracts Early payoff fee. This value is not floored at zero, so a negative number means the fee is larger than the interest saved.
net_interest_savings_after_fee = gross_interest_saved - early_payoff_fee
Months paid off sooner compares the regular payoff month with the payoff month from your plan.
payoff_time_saved_months = regular_payoff_months - plan_payoff_months
Estimated payoff date is calculated by adding Payoff month with your plan to the Start date in calendar months.
payoff_date_with_plan = start_date plus payoff_month_number calendar months
Worked mini-example
Suppose Current loan balance is $1,000, Annual interest rate is 12%, Current monthly payment is $100, Extra paid each month is $0, One-time extra payment is $300, One-time payment month is 5, and Early payoff fee is $0. The regular plan pays about $58.98 in interest. The extra-payment plan pays about $45.20 in interest and finishes in month 8 instead of month 11. Interest saved before fees is about $13.79, Months paid off sooner is 3, and Interest saved after early payoff fee is also about $13.79 because the fee is $0.