Home Equity Calculator Payment Comparison

A home equity calculator payment comparison estimates monthly payments on a home equity loan or line of credit using the amount borrowed, APR, and repayment term. Enter the figures supplied by a lender to compare the modeled payment and total interest; a fixed-payment loan and a variable-rate line of credit may not follow the same schedule.

Formula

The calculator uses the standard fixed-payment amortization formula. It first calculates the monthly payment, then estimates total interest by multiplying that payment by the number of monthly payments and subtracting the amount borrowed.

• p = loan principal, or amount borrowed, in dollars.
• apr = annual percentage rate entered as a percentage, such as 8 for 8% per year.
• r = monthly interest rate, calculated as apr / 1200.
• n = number of monthly payments, calculated as years × 12.
• pmt = monthly payment in dollars: p × r / (1 − (1 + r)⁻ⁿ), rounded to the nearest cent.
• int = estimated total interest in dollars: pmt × n − p.

This model assumes equal monthly payments that include principal and interest. It is not a quote and does not calculate an available borrowing amount from home equity.

Worked Example

Using the calculator’s defaults—$20,000 borrowed, 8% APR, and five years—the number of payments is 5 × 12 = 60. The monthly rate is 8 / 1200 = 0.0066667.

Monthly payment = 20,000 × 0.0066667 / [1 − (1 + 0.0066667)⁻⁶⁰] = $405.53 when rounded to cents. Estimated total paid = $405.53 × 60 = $24,331.80. Estimated interest = $24,331.80 − $20,000 = $4,331.80.

Assumptions

• The interest rate stays fixed for the entire modeled term.
• Payments are made monthly, with the first regular payment one month after borrowing.
• Interest compounds monthly at APR / 12.
• Fees, taxes, insurance, escrow, and any costs not entered are excluded.

How to Compare Home Equity Payments

For a meaningful comparison, use the same loan amount and a consistent set of lender-provided figures. If one offer has a different term or APR, the payment difference reflects more than one factor. Run separate calculations to see how each quoted combination changes the modeled payment and interest.

1. Enter the amount you are evaluating, not the maximum amount a lender might make available.
2. Use the quoted APR and term for each option. Confirm whether the lender’s figures include fees or a temporary rate.
3. Compare the monthly payment alongside estimated total interest and the number of payments.
4. Check the lender’s payment schedule and disclosures for charges or features this calculator does not model.

For example, a longer term generally spreads repayment over more months, which can reduce the modeled payment while increasing the number of months interest accrues. A shorter term can raise the monthly payment while reducing the time over which interest is calculated. These are formula effects, not a prediction of what a lender will offer.

Loan Versus Line of Credit

A home equity loan generally provides a specified amount that is repaid through scheduled payments. A home equity line of credit (HELOC) allows borrowing under a credit limit, and its interest rate may vary. A single fixed-rate amortization calculation can illustrate a loan payment, but it cannot fully represent a line with changing balances, variable rates, an initial draw period, or later repayment terms.

For a HELOC comparison, the result is only a hypothetical illustration if you enter a balance and rate as though they remain unchanged and are repaid in equal installments over the selected term. Actual required payments may be calculated differently. Ask the lender for the payment schedule, whether the rate can change, and how payments are determined at each stage.

Costs and Common Comparison Problems

The displayed payment is principal and interest only. It may differ from a lender’s quoted amount if the quote includes fees or other charges, uses a different payment date convention, or reflects a variable rate. The total-interest result is also based on the rounded monthly payment, so it is an estimate rather than an exact payoff statement.

• Comparing different loan amounts: Normalize the amount when isolating the effect of APR or term.
• Confusing APR with a monthly rate: Enter the annual APR as a percentage; do not enter 0.0067 for a 0.67% monthly rate.
• Treating a HELOC rate as fixed: A changing rate or balance can change the required payment.
• Ignoring excluded charges: Request an itemized payment and cost breakdown from the lender.
• Rounding differences: Lender systems may calculate with additional precision or adjust a final payment by a small amount.

Home equity borrowing uses the home as collateral. Missing payments can have serious consequences, including risk to the home. The calculator does not assess a household’s finances, eligibility, available equity, or ability to make payments.

Frequently Asked Questions

How do I compare home equity loan payments?
Enter each option’s quoted amount, APR, and term, then compare modeled monthly payment and total interest. Keep in mind that fees and payment features may differ.

Does this calculator work for a HELOC?
It can show a hypothetical fixed-rate repayment for a stated balance and term. It does not model a variable rate, changing draws, or a HELOC’s specific payment phases.

Why is my lender’s payment different?
The lender may include charges, use different assumptions, apply a changing rate, or calculate payments under terms not represented here. Check the lender’s detailed disclosure and payment schedule.

Does a longer term lower the payment?
For the same principal and fixed APR, spreading repayment over more monthly payments lowers the modeled payment, but generally increases total interest under this formula.

Does the calculator tell me how much equity I can borrow?
No. It estimates payments for an amount you enter. A lender determines any available amount using its own information and process.

This result is an estimate, and the lender’s disclosure gives the exact figures.

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in p | Loan amount | $ | 20000 | 1 | 100000000
in apr | Interest rate (APR) | % | 8 | 0.01 | 100
in yrs | Loan term | years | 5 | 0.0833 | 50
out pmt | Monthly payment | $ | p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)) | 2
out int | Total interest | $ | pmt * yrs * 12 - p | 2