# HELOC Calculator – Home Equity Line of Credit

URL: https://speedycalculator.com/calculators/finance/heloc/
Last updated: 2026-10-25

> The HELOC calculator works out your available home equity line, the interest-only payment during the draw period, the higher amortizing payment once repayment starts, and the total interest – from your home value, mortgage balance, maximum CLTV, draw amount and rate.

## Inputs

- Home value
- Mortgage balance
- Maximum combined LTV (%)
- Amount drawn
- HELOC interest rate (%)
- Draw period (years)
- Repayment period (years)
- Closing costs and fees

## Results

- Maximum credit line
- Interest-only payment during the draw period
- Payment during repayment
- Interest during the draw period
- Interest during repayment
- Total cost (interest + fees)
- Combined LTV with the draw

## Formula

```
Maximum line = home value × CLTV limit − mortgage balance
Draw-period payment (interest only) = balance × rate ÷ 12
Repayment payment = pmt(rate ÷ 12, repayment months, balance)
```

## Explanation

HELOCs typically have a 10-year draw period followed by 20 years of repayment, with a variable rate tied to the prime rate. Payment shock when the draw period ends is the biggest risk – plan for the higher payment.

### How to use the HELOC Calculator – Home Equity Line of Credit

- **Home value**
- **Mortgage balance**
- **Maximum combined LTV**
- **Amount drawn**
- **HELOC interest rate**
- **Draw period**
- **Repayment period**
- **Closing costs and fees**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the home value, mortgage balance, lender's CLTV limit, the amount you draw, the rate, the draw and repayment periods and fees.

### Tips

- Compare loans by APR and total cost, not just the monthly payment.
- Extra payments go straight to principal and can save a lot of interest.
- Pay off the highest-rate debt first if you want to save the most money.
- Check for prepayment penalties before paying a loan off early.

### Common mistakes to avoid

- Stretching a loan term to lower the payment without seeing the extra interest.
- Paying only the minimum on credit cards.
- Forgetting fees that are rolled into the loan.

### Inputs explained

FieldWhat to enterHome valueAmount in your currencyMortgage balanceAmount in your currencyMaximum combined LTVIn %Amount drawnAmount in your currencyHELOC interest rateIn %Draw periodIn yearsRepayment periodIn yearsClosing costs and feesAmount in your currency

### What each result means

- **Maximum credit line** = max([Home value]×[Maximum combined LTV]÷100 - [Mortgage balance], 0)
- **Interest-only payment during the draw period** = [Amount drawn]×[HELOC interest rate]÷1200
- **Payment during repayment** = pmt([HELOC interest rate]÷1200, [Repayment period]×12, [Amount drawn])
- **Interest during the draw period** = [Interest-only payment during the draw period]×[Draw period]×12
- **Interest during repayment** = [Payment during repayment]×[Repayment period]×12 - [Amount drawn]
- **Total cost (interest + fees)** = [Interest during the draw period] + [Interest during repayment] + [Closing costs and fees]
- **Combined LTV with the draw** = ([Mortgage balance] + [Amount drawn])÷[Home value]×100

### Example values

How the main result changes when **Home value** changes and everything else stays at the example values above:

Home valueInterest-only payment during the draw period250,000387.5375,000387.5500,000387.5625,000387.5750,000387.51,000,000387.5

## Worked example

Inputs — Home value: $500,000; Mortgage balance: $280,000; Maximum combined LTV: 85 %; Amount drawn: $60,000; HELOC interest rate: 7.75 %; Draw period: 10 years; Repayment period: 20 years; Closing costs and fees: $500.

Results — Maximum credit line = $145,000.00; **Interest-only payment during the draw period = $387.50**; Payment during repayment = $492.57; Interest during the draw period = $46,500.00; Interest during repayment = $58,216.59; Total cost (interest + fees) = $105,216.59; Combined LTV with the draw = 68 %.

## FAQ

**How much can I borrow with a HELOC?**
Usually up to 80–90% of your home's value minus your mortgage.

**Are HELOC rates variable?**
Most are, based on the prime rate plus a margin.

**Is HELOC interest tax-deductible?**
Only if used to buy, build or substantially improve the home.

**What formula does the HELOC Calculator – Home Equity Line of Credit use?**
Maximum line = home value × CLTV limit − mortgage balance.


## Sources

- [Consumer Financial Protection Bureau](https://www.consumerfinance.gov/)