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 | ||||
How This HELOC Interest Calculator Works
This calculator estimates what you might pay on the amount currently drawn from your HELOC. During the draw period, it models interest-only payments unless you choose to add extra principal. After the draw period, the remaining balance converts into a standard principal-and-interest repayment schedule.
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.
Frequently Asked Questions
HELOC Draw Period vs Repayment Period
A HELOC usually has two phases. The draw period is more flexible and may allow interest-only payments. The repayment period is less flexible and generally comes with higher required payments because you are paying back principal and interest.
| Feature | Draw Period | Repayment Period |
|---|---|---|
| Typical payment structure | Interest-only or low minimum payment | Principal + interest |
| Balance behavior | Usually stays flat unless you pay extra principal | Usually declines each month |
| Cash access | You may still draw funds | New draws usually stop |
| Monthly payment level | Lower | Higher |
| Main risk | Underestimating future payment shock | Budget strain from larger required payment |