Assumption: the drawn HELOC balance stays constant during the draw period unless you add extra principal, then the remaining balance amortizes over the repayment period with monthly payments.
| Period | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| Enter HELOC details above to see the schedule | ||||
What are interest-only HELOCs? A Simple Guide
Home equity lines of credit (HELOCs) are revolving credit lines secured by your home's equity. Similar to a credit card, you borrow what you need up to your permitted amount and repay it over time.
You are only obligated to pay the interest that has accumulated on your outstanding balance—not the principal—during the interest-only term, which usually lasts the first five to ten years. In comparison to a completely amortizing loan, this results in much less monthly payments. The flexibility of a HELOC is one of its biggest advantages. You can draw funds as needed, repay them, and borrow again — all while keeping your monthly obligation manageable during the draw period.
How This Interest-Only HELOC Calculator Works
This tool requires just two inputs to calculate your estimated monthly payment
- Loan amount : The outstanding balance you've drawn from your HELOC.
- Interest rate : The annual interest rate on your HELOC (usually variable)
Based on these inputs, the calculator outputs your monthly interest-only payment — the minimum amount you'd owe each month during the draw period. While this tool focuses on HELOCs, a general interest only calculator can help you explore other loan types, such as interest-only mortgages or personal loans.
Payment Formula
Repayment Payment = Balance x [i x (1+i)^n] / [(1+i)^n - 1]
Extra principal paid during the draw period reduces the balance before repayment begins.
What the Results Mean
- Interest-Only Payment: monthly payment during the draw period if you pay only interest.
- Repayment Payment: monthly payment once principal and interest both kick in.
- Total Paid: total of all monthly payments across the full modeled term.
- Total Interest: estimated borrowing cost across the full term.
- Payment Jump: how much monthly cost may rise when repayment begins.
Example Calculation
Using the interest-only formula, a $100,000 HELOC at 6% breaks down like this: ($100,000 × 0.06) ÷ 12 = $500/month. You're covering interest only, so your principal balance stays untouched throughout the draw period. This means on a $100,000 HELOC balance at 6%, you'd owe just $500 per month—without touching the principal at all.
Key Factors That Affect Your HELOC Payment
Several variables can influence how much you pay on a HELOC:
- Interest rate : Most HELOCs carry a variable rate tied to the prime rate. When rates rise, so does your payment.
- Loan amount : The more you draw from your credit line, the higher your monthly interest payment.
- Credit score : A higher credit score typically qualifies you for a lower interest rate, reducing your monthly payment.
- Repayment period : Once the draw period ends, your payments will include both principal and interest, increasing your monthly obligation significantly.
- Market conditions : Changes in the federal funds rate directly affect HELOC rates, since most are variable.
Benefits of Interest-Only HELOC Payments
Borrowers select interest-only HELOCs for a number of pragmatic reasons:
- Improved cash flow: The money saved might be used for other costs, investments, or home renovations.
- Reduced monthly payments: You can minimize your short-term cash outflow by merely paying interest.
- Flexibility: Your payment only shows what you've really utilized because you have control over how much you borrow and when.
Risks to Consider
Interest-only HELOCs aren't without downsides. Before choosing this option, consider the following:
- Payment increases later — When the repayment period begins, your payment will jump substantially because you'll now be paying down both principal and interest.
- Variable rates — If market interest rates rise, your monthly payment will increase — even during the interest-only phase.
- Higher long-term cost — Deferring principal repayment means you pay more interest overall across the life of the loan.
Interest-Only HELOC vs Standard HELOC
The main difference between these two options comes down to what you pay each month:
| Feature | Interest-Only HELOC | Standard HELOC |
|---|---|---|
| Draw period payments | Interest only | Principal + interest |
| Monthly payment | Lower | Higher |
| Long-term cost | Higher | Lower |
| Cash flow benefit | High | Moderate |
An interest-only HELOC is best when you need to minimize short-term costs. A standard HELOC builds equity faster. Unlike a standard interest only calculator for general loans, this tool is tailored specifically for HELOC payment calculations, accounting for the revolving nature of the credit line.