Complete guide
HELOC calculator for draw and repayment periods
Enter home value, mortgage debt, credit line, current draw, rate and both phases. Calculator24 estimates utilization, CLTV, interest-only draw payment, later amortizing payment and total modeled interest.
How a HELOC works
A home equity line of credit is revolving debt secured by the home. The draw period may allow borrowing and repayment; a later repayment period can require principal and interest.
Draw-period payment
This scenario assumes no further draws and interest-only monthly payments on the current balance. Actual minimum-payment rules can include principal, fees or a floor.
interest-only payment = balance × rate ÷ 12 ÷ 100Repayment-period payment
At the modeled transition, the unchanged balance is amortized across the repayment years. That payment may be materially higher than the interest-only amount.
Credit utilization and CLTV
Utilization compares current balance with the line limit. Combined LTV uses the full credit limit conservatively because a lender may underwrite available credit as potential debt.
Variable-rate and collateral risk
HELOC rates are often variable, so a constant-rate projection is one scenario. CFPB warns that the home is collateral; inability to repay can put it at risk.
Two HELOC phases
| Phase | Modeled payment | Balance behavior |
|---|---|---|
| Draw | Interest only | Unchanged without new draws |
| Repayment | Principal + interest | Falls to zero over term |
Frequently asked questions
What is a HELOC?
It is a revolving line of credit secured by home equity.
Why can the repayment payment jump?
Principal begins amortizing in addition to interest.
Does this model future draws?
No. It assumes the current balance remains constant during the draw phase.
Can the interest rate change?
Often yes; this calculator holds the entered rate constant for comparison.
What does HELOC utilization mean?
It is the current HELOC balance divided by the credit limit.
What to keep in mind
HELOC rates and balances can change. This constant-rate, no-further-draw scenario is an estimate and your home secures the debt.
Results display up to 8 decimal places; exported numbers preserve calculation precision. This is a calculation summary, not an official certificate.