A HELOC lets you borrow against your home equity, usually up to about 80% to 85% of your home’s value minus your mortgage.
For example, on a $400,000 home with a $250,000 mortgage and an 80% limit, you could have a line of up to $70,000. At an 8% rate, borrowing $50,000 costs about $333 a month interest-only, then $418 a month over 20 years of repayment.
AdvertisementUse the free calculator below to see your equity, your maximum credit line, your payments in both stages and your total interest.
You can also test what a higher rate would do to your payment.
HELOC Calculator
Enter your numbers
What your home is worth today. Use a recent appraisal or a realistic estimate.
What you still owe on your mortgage and any other loans secured by the home.
Include other loans on the home
The highest total of all loans against your home, as a percent of its value. Lenders set this limit, so ask yours.
Set by your lender. Ask them
How much you plan to borrow from the line of credit, in dollars.
The yearly interest rate on the line. HELOCs usually have a variable rate, so this can change. Use your lender’s quote if you have one.
Prime is 7.00% (Oct 29, 2026). Rates are prime plus a margin
The years you can borrow from the line. Payments are often interest-only during this time, but check your terms.
Years you can borrow
The years you repay the balance after the draw period ends. Payments include principal and interest.
Years to repay after the draw
How many percentage points to add to your rate to see a higher-rate payment. HELOC rates are usually variable.
Added to your rate
Your inputs
| Home value | $400,000 |
| Mortgage balance | $250,000 |
| Maximum combined loan-to-value | 80% |
| Amount to borrow | $50,000 |
| HELOC interest rate | 8.0% |
| Draw period | 10 years |
| Repayment period | 20 years |
| Rate increase tested | 2 points |
Estimated monthly payment during the draw period
$333
Interest-only, then $418 a month for 20 years of repayment.
How much you can borrow
| Home equity (value minus mortgage balance) | $150,000 |
| Estimated maximum credit line | $70,000 |
| Combined loan-to-value after borrowing | 75.0% |
Payments and interest
| Payment during repayment period | $418 |
| Interest paid during the draw period | $40,000 |
| Interest paid during repayment | $50,373 |
| Total interest | $90,373 |
If your rate rises
| Draw-period payment at the higher rate | $417 |
| Repayment payment at the higher rate | $483 |
This is an estimate. It assumes you borrow the full amount at the start, pay interest only during the draw period and keep the same rate. Fees are not included.
To save your estimate: press Ctrl+P (Windows) or Cmd+P (Mac) and choose Save as PDF. Only the results print.
HELOC Checklist
Tick each item as you finish. You are ready to apply when the counter reaches 10.
How the HELOC Calculator Works
- It finds your equity. Home value minus your mortgage balance.
- It applies the lender’s limit. Home value times the combined loan-to-value limit, minus your mortgage, gives the estimated maximum line.
- It estimates payments. During the draw period the payment is interest only. In repayment, the balance is paid off with principal and interest over the years you enter.
- It tests a higher rate. Adding points to your rate shows how a variable rate could change both payments.
Home Equity and Maximum Line Chart
This chart uses an 80% combined loan-to-value limit.
| Home value | Mortgage balance | Home equity | Max line at 80% limit |
|---|---|---|---|
| $300,000 | $200,000 | $100,000 | $40,000 |
| $400,000 | $250,000 | $150,000 | $70,000 |
| $400,000 | $300,000 | $100,000 | $20,000 |
| $500,000 | $300,000 | $200,000 | $100,000 |
| $600,000 | $350,000 | $250,000 | $130,000 |
| $750,000 | $400,000 | $350,000 | $200,000 |
Today’s Rates
The prime rate was 7.00% as of October 29, 2026, after the Federal Reserve held its target range at 3.75% to 4.00%. HELOC rates are usually prime plus a margin that depends on your credit and equity, so your offer can be higher or lower. For comparison, Freddie Mac’s survey showed a 30-year fixed mortgage average of 7.24% on October 29, 2026.
Things to Know Before You Borrow
- The rate is usually variable. The CFPB says payments can change from month to month, and some lenders let you convert part of the balance to a fixed rate.
- Your home is collateral. Missed payments can lead to foreclosure.
- Payments can jump. When the draw period ends, principal is added to the payment.
- Taxes. The IRS has said the interest is deductible only when the money is used to buy, build or substantially improve the home that secures the loan. Check current guidance.
- Fees. Ask about appraisal, annual and early closure fees.
HELOC Uses That Can Make Sense
- Home improvements that add value.
- Debt consolidation, if you stop running up the old debts.
- Emergency reserve you draw on only when needed.
- Education or medical costs when other options cost more.
Mistakes to Avoid
- Borrowing the maximum. Borrow only what you need.
- Ignoring rate changes. Test a higher rate first.
- Paying interest only forever. The balance does not shrink.
- Using it for spending you cannot repay. Your home is at risk.
- Skipping the fee list. Fees change the real cost.
Frequently Asked Questions
What is a HELOC?
A home equity line of credit is a revolving credit line secured by your home. You borrow what you need during a draw period, often 10 years, then repay during a repayment period. Your home is the collateral, so missed payments can put it at risk.
How much can I borrow with a HELOC?
Lenders set a maximum combined loan-to-value limit, often around 80% to 85%. Multiply your home value by that limit and subtract your mortgage balance. On a $400,000 home with a $250,000 mortgage and an 80% limit, that is $70,000. Ask your lender for its exact limit.
What is the interest rate on a HELOC?
Most HELOCs have a variable rate tied to the prime rate plus a margin. Prime was 7.00% as of October 29, 2026, after the Fed held its target range at 3.75% to 4.00% on October 28. Your rate depends on your credit, equity and lender.
Are HELOC payments interest-only?
Often during the draw period, yes. Interest-only means you do not reduce the balance. When the repayment period starts, payments include principal and interest and usually rise. Check your terms.
What happens if my rate goes up?
Because the rate is usually variable, your payment can change. The CFPB notes that payments on variable-rate loans may change each month. Use the “Test a rate increase” box to see the effect.
Is HELOC interest tax deductible?
It can be, but only in limited cases. The IRS has said interest on home equity loans and lines is deductible only when the money is used to buy, build or substantially improve the home that secures the loan, within the overall mortgage debt limits. Check current IRS guidance or ask a tax professional.
What is the difference between a HELOC and a home equity loan?
A HELOC is a revolving line with usually a variable rate, so you borrow as needed. A home equity loan gives a lump sum with a fixed rate and a fixed payment. Choose by how predictable you need the payment to be.
Does a HELOC have fees?
Many lenders charge an appraisal, application, annual or closing fees, and some charge for closing the line early. The calculator leaves fees out, so ask for a full fee list.
Can I lose my home with a HELOC?
Yes. A HELOC is secured by your home, so if you cannot repay, the lender can foreclose. Borrow only an amount you can repay even if the rate rises.
Is this calculator a loan offer?
No. It gives an estimate from the numbers you enter. Only a lender can approve a line after checking your credit, income and home value. This page offers general information, not financial advice.
Conclusion
A HELOC can be a flexible way to use home equity, but the variable rate and the home as collateral make it worth planning. Enter your numbers, test a higher rate and borrow only an amount you can repay.
Related Reading
- Mortgage calculator with taxes and insurance
- How much house can I afford calculator
- Rent vs buy calculator
- Car loan interest calculator
Sources: PrimeRates, Prime rate and Fed decision, Oct 29, 2026; CFPB, What is a variable-rate loan?; IRS, IR-2018-32 on home equity loan interest; Freddie Mac Primary Mortgage Market Survey, Oct 29, 2026.