Interest-Only HELOC Calculator
During your draw period, you only pay interest — but that number changes as your balance grows. See what you owe at every stage of the draw.
About this tool
The draw phase is the most flexible part of a HELOC — but it's also the phase that can lull borrowers into a false sense of affordability. Low interest-only payments during draw can give way to a significant P&I payment at repayment start.
How to use it
Quick steps to get the most out of this utility.
- 1
Enter your credit limit and draw plan
How much credit you have and what you plan to draw.
- 2
Set your HELOC rate
Current rate — remember it's variable in real life.
- 3
Set draw period length
Usually 10 years, but some HELOCs are 5 or 15 years.
- 4
See interest-only payments
Draw-phase payments plus a preview of what repayment will cost.
Understanding Interest-Only HELOC Payments
Interest-only payments sound great — they're lower — but they can mask the true cost of borrowing. At 8.5% on $50,000, you pay $354/month during draw but still owe $50,000 when repayment starts. Then you amortize that $50,000 over 20 years at P&I, which is $434/month — an 80/month jump on top of the transition. The interest-only phase is a temporary grace period, not a permanent payment structure.
Frequently asked questions
What happens if I only pay interest during the draw period?+
The principal stays exactly where it is — none of it gets paid down. Your entire borrowed amount converts to an amortizing loan at repayment start, which is why the payment jumps.
Can I make principal payments during the interest-only period?+
Yes — most HELOCs allow voluntary principal paydown. Any principal you pay reduces what amortizes in the repayment phase, lowering that payment.
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