HELOC CalculatorFree online financial calculator — instant results, no sign-up
Interest-only draw payment and repayment phase payment.
Estimates only, based on the inputs and assumptions shown. This is not financial, investment, tax, or legal advice. Prices, rates and local rules may change; crypto scenarios do not predict returns. Confirm important decisions with a qualified professional.
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About the HELOC Calculator
This calculator determines the monthly payment for a home equity line of credit (HELOC) across its two distinct phases: the interest-only draw phase and the amortized repayment phase. It helps homeowners prepare for the transition in monthly cash flow when borrowing against home equity.
- Amount drawn
- Total balance drawn from the credit line, in dollars ($). Typical amounts range from $5,000 to $500,000.
- Rate
- Annual interest rate as a percentage (%). Typical HELOC rates range from 4% to 15%.
- Repayment period
- Duration of the repayment phase in years, usually between 5 and 20 years.
Formula and method
Interest-only payment = P × (r / 1200) Repayment phase payment = P × [ (r / 1200) × (1 + r / 1200)^n ] / [ (1 + r / 1200)^n − 1 ]
- PAmount drawn (principal balance)
- rAnnual interest rate in percentage form
- nTotal number of monthly repayment periods (years × 12)
The interest-only payment is calculated by multiplying the principal balance by the monthly interest rate (annual rate divided by 1,200). The repayment phase payment is computed using standard loan amortization formula over the total number of repayment months (years multiplied by 12). Both outputs are rounded to two decimal currency places.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Amount drawn50000 $
- Rate8.5 %
- Repayment period20 years
Results
- Interest-only payment$354.17
- Repayment phase payment$433.91
How to use the HELOC Calculator
- 1Divide the annual interest rate by 1,200 to find the monthly interest rate.
- 2Multiply the drawn balance by the monthly interest rate to find the draw phase payment.
- 3Multiply the repayment period in years by 12 to find the total number of repayment months.
- 4Apply the fixed amortization formula to calculate the monthly principal-plus-interest payment for the repayment phase.
Reading your result
The 'Interest-only payment' shows the minimum monthly cost required while you are actively borrowing and only servicing interest. The 'Repayment phase payment' indicates the higher monthly amount needed to fully pay off the borrowed principal and ongoing interest over the remaining term.
Limitations
The calculation assumes a fixed interest rate throughout both phases, whereas most HELOCs have variable rates that adjust with benchmark interest rates. It also assumes no additional draws or early principal prepayments are made, and does not include annual line fees or origination costs.
Common questions
Why does the payment increase significantly during the repayment phase?+
During the draw period, payments only service monthly interest. Once the repayment phase begins, the line closes to new draws and payments must cover both interest and a portion of the principal balance to pay the loan off completely.
Can I pay down principal during the draw phase?+
Yes. While lenders typically require only interest during the draw period, paying extra toward the principal reduces total interest costs and lowers the eventual repayment phase payment.
What happens if my HELOC has a variable interest rate?+
Variable rates change whenever the underlying benchmark rate (such as the prime rate) shifts. If the rate increases, both your interest-only payment and your repayment phase payment will increase.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
Further reading
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Results are estimates for informational purposes and are not financial, medical or legal advice.