HELOC Calculator
Model interest-only HELOC draws, the balance entering repayment, later amortized payments, and equity capacity.
Content updated August 3, 2026
| Phase and month | Payment | Balance |
|---|---|---|
| Draw month 12 | $387.50 | $62,000.00 |
| Draw month 24 | $462.50 | $74,000.00 |
| Draw month 36 | $537.50 | $86,000.00 |
| Draw month 48 | $612.50 | $98,000.00 |
| Draw month 60 | $687.50 | $110,000.00 |
| Repayment month 12 | $1,115.69 | $106,364.13 |
| Repayment month 24 | $1,115.69 | $102,387.19 |
| Repayment month 36 | $1,115.69 | $98,037.18 |
| Repayment month 48 | $1,115.69 | $93,279.12 |
| Repayment month 60 | $1,115.69 | $88,074.71 |
| Repayment month 72 | $1,115.69 | $82,382.10 |
| Repayment month 84 | $1,115.69 | $76,155.48 |
| Repayment month 96 | $1,115.69 | $69,344.76 |
| Repayment month 108 | $1,115.69 | $61,895.15 |
| Repayment month 120 | $1,115.69 | $53,746.71 |
| Repayment month 132 | $1,115.69 | $44,833.89 |
| Repayment month 144 | $1,115.69 | $35,084.99 |
| Repayment month 156 | $1,115.69 | $24,421.57 |
| Repayment month 168 | $1,115.69 | $12,757.85 |
| Repayment month 180 | $1,115.69 | $0.00 |
Simplified scenario: each monthly draw occurs first, the draw-phase payment equals interest only, rates remain at the entered values, and repayment fully amortizes the ending balance. Real HELOC rates, minimums, draw access, fees, freezes, balloon terms, and payment timing can differ. The home secures the line.
A home equity line of credit is revolving, open-end credit secured by a home. During its draw period, a borrower may take repeated advances up to the available line; after that period ends, further draws stop and repayment terms control how the balance is paid.
This calculator intentionally separates those phases. It models a constant draw at the start of each month and an interest-only payment during the draw phase, then fully amortizes the ending balance during repayment using a second rate scenario.
The HELOC formula
Draw month: Bₘ = Bₘ₋₁ + draw; paymentₘ = Bₘ × draw APR/12. Repayment payment = Bᴅ·r ÷ [1−(1+r)⁻ⁿ]Bᴅ = balance after the last draw · r = repayment annual rate ÷ 12 · n = whole repayment months · modeled credit limit = max(0, home value × max CLTV − existing liens).
Worked example
Starting at $50,000, adding $1,000 at the start of each month for 12 months, and paying interest only at 6% produces a $62,000 balance and $3,390 of draw-phase interest. Repaying $62,000 over 10 years at 8% is about $752.23 per month.
Assumptions, rounding, and limitations
Assumptions
- Home value, liens, balances, advances, and outputs use the selected currency.
- The modeled credit limit applies only the user-entered maximum combined LTV; it is not a lender commitment.
- One constant advance occurs at the start of every draw month and the payment then equals that month's interest only.
- Draw and repayment rates remain at their separately entered annual scenario values, although real HELOC rates are commonly variable.
- No further advances occur after the draw period and the full ending balance amortizes over the entered repayment term.
Rounding: Monthly balances, interest, principal, and payments retain floating-point precision. Currency displays use up to two decimal places, milestone rows show each completed year plus a partial final year, and the final repayment uses the exact remaining balance.
Limitations
- Supports money inputs and the repayment balance up to 1 trillion, annual rates from 0% to 100%, combined LTV above 0% through 100%, and each phase from 1–600 whole months.
- Does not model changing indices or margins, rate caps, minimum-payment floors, principal payments during draw, irregular draws, reused credit after repayment, fees, frozen or reduced lines, balloon terms, taxes, insurance, first-mortgage payments, delinquency, or refinancing.
- This is an educational scenario, not a creditor disclosure, offer, appraisal, credit-limit prediction, tax conclusion, or individualized financial or legal advice. The home secures the line.
Sources
- What is a home equity line of credit (HELOC)? — Consumer Financial Protection Bureau
- Regulation Z § 1026.40 — Requirements for home equity plans — Consumer Financial Protection Bureau
- What fees can my lender charge if I take out a HELOC? — Consumer Financial Protection Bureau
A transparent two-phase scenario
Each draw month starts by adding the entered advance to the current balance. Interest is then calculated at the entered draw-period annual rate divided by 12, and the modeled payment equals that interest, so principal does not fall during the draw phase.
At the transition, no more advances occur. The complete ending balance is converted to equal monthly principal-and-interest payments over the entered repayment period at the entered repayment-rate scenario, with the final payment adjusted to the exact remaining balance.
Why actual HELOC payments can differ
CFPB guidance says HELOCs usually have variable rates, payments can change, and some plans can require substantially higher payments or even a balloon when the draw period ends. Regulation Z disclosures describe the draw and repayment periods, minimum-payment method, variable-rate terms, and possible balloon payment.
The constant rates and interest-only rule here are user-selected comparison assumptions, not predictions. Review the creditor's index, margin, caps, minimum-payment formula, fees, draw rules, repayment term, and conversion options.
Frequently asked questions
▶When does each modeled draw occur?
The entered amount is added at the start of each draw month before that month's interest-only payment is calculated.
▶Why does the balance grow during the draw period?
The model pays interest only and adds a new advance each month. Because no principal is repaid, the balance grows by the total new draws.
▶Does the repayment payment stay fixed in real life?
Not necessarily. This calculator holds the repayment rate fixed for one scenario; actual HELOC rates and payments can change under the agreement.
▶Is the modeled credit limit guaranteed?
No. It is only home value multiplied by your entered combined-LTV ceiling minus existing liens. A creditor may set, reduce, freeze, or otherwise limit available credit under the plan terms and applicable rules.
▶Does the total include HELOC fees?
No. Application, appraisal, title, annual, inactivity, conversion, cancellation, and other fees are excluded unless they are already part of the opening balance.
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Open calculator →Disclaimer: HELOC Calculator results are estimates for general information and education only, and are not financial, tax, legal or medical advice. Verify important decisions with a qualified professional.