What is the monthly payment on a $100,000 HELOC?

Interest-only during the draw period: about $708/month at 8.5%, ranging from $583 at 7% to $833 at 10%. In the 20-year repayment period the same balance requires about $868/month at 8.5%.

How much income do I need for a $100,000 HELOC?

Lenders qualify you at the fully amortizing payment — roughly $868/month at 8.5% — and generally want total debt payments under about 43% of gross monthly income. As a rough benchmark, that means around $2,000/month of DTI headroom before the HELOC, alongside sufficient home equity (typically $120,000+ beyond your mortgage at an 80% combined LTV cap).

Is interest on a $100,000 HELOC tax-deductible?

Only if the funds are used to buy, build, or substantially improve the home securing the loan, per IRS Publication 936, and only if you itemize deductions. Using the funds for debt consolidation, tuition, or general spending is not deductible.

How much interest does a $100,000 HELOC cost?

At a constant 8.5%: about $85,000 if you pay interest-only for a full 10-year draw period, plus roughly $108,000 total once a 20-year repayment period completes — together more than the original balance. Voluntary principal payments during the draw period are the main way to cut this.

$100,000 HELOC Payment Calculator (2026)

The Answer: $583–$833 Interest-Only, $775–$965 in Repayment

The quick answer

The payment on a $100,000 HELOC balance at a typical 8.5% rate is about $708/month interest-only during the draw period, rising to roughly $868/month when the balance amortizes over a 20-year repayment period. Every payment here scales exactly 2× the $50,000 figures — the formula is linear in the balance. Run your own numbers with the interest-only HELOC calculator.

Key takeaways

Every payment on this page is exactly 2× the corresponding $50,000 HELOC figures — interest-only and amortized payments both scale linearly with balance.
Interest is only tax-deductible on a HELOC if the funds go toward "buying, building, or substantially improving" the home securing the loan, per IRS Publication 936 — not for debt consolidation or general spending.
Most lenders qualify you at the fully-amortizing repayment payment, not the interest-only teaser — budget to that number, not the lower one advertised.
A $100,000 line typically requires $120,000+ of equity beyond your mortgage balance, under an 80–85% combined loan-to-value cap.

Suburban house exterior representing home equity used to secure a large HELOC. — A six-figure HELOC is sized off your home's equity, but qualifying is really about whether you can carry the repayment-phase payment, not the lower interest-only one. Photo by Breno Assis on Unsplash

HELOC rate	Interest-only payment (draw period)	20-yr repayment payment	Interest over full 10-yr IO draw
7.0%	$583.33	$775.30	$70,000
7.5%	$625.00	$805.59	$75,000
8.0%	$666.67	$836.44	$80,000
8.5%	$708.33	$867.82	$85,000
9.0%	$750.00	$899.73	$90,000
9.5%	$791.67	$932.13	$95,000
10.0%	$833.33	$965.02	$100,000

$100,000 drawn balance. Interest-only = balance × rate ÷ 12; repayment column uses standard 240-month amortization. The last column assumes the rate holds for the full draw period — in practice it floats with prime.

Interest-Only Payment = Balance × (Rate ÷ 12)

Variables

Balance — drawn amount ($100,000), not your credit limit

Rate — current annual rate as a decimal (0.085 for 8.5%)

Example: $100,000 × (0.085 ÷ 12) = $708.33 per month, with the full $100,000 still owed afterwards.

The scale is what makes a six-figure line dangerous on autopilot: interest-only for a full 10-year draw at 8.5% costs about $85,000 with zero principal reduction, and completing a 20-year repayment period afterwards brings total interest to roughly $108,000 — more than the amount borrowed. A 1-point prime increase moves this payment by about $83/month immediately.

Run the numbers

Interest-Only HELOC Calculator

See both phases of a $100,000 line — the interest-only payment now and the exact repayment-period jump — plus how voluntary principal changes the picture.

Calculate your HELOC payment

Qualifying for (and Surviving) a $100,000 Line

Lenders typically cap combined loan-to-value (your mortgage plus the HELOC limit) at 80–85% of the home's value. Supporting a $100,000 line therefore generally requires at least $120,000–$125,000 of equity beyond your mortgage balance on an appraised-value basis, along with debt-to-income headroom for the fully amortizing payment — most underwriters qualify you at the repayment-phase number (or higher, stress-tested), not the interest-only teaser.

Budget for the repayment payment from day one

The gap between $708 interest-only and $868 in repayment is $160/month at a constant rate — and the rate isn't constant. If you can't comfortably carry the right-hand column of the table above, the responsible draw is smaller than the approved line. The Federal Reserve's HELOC booklet — the disclosure your lender is required to give you — walks through exactly this risk.

Paying voluntary principal during the draw period defuses most of it: $600/month of principal on top of interest clears $100,000 in about 11 years. Build that plan with the HELOC payoff calculator, or compare against a fixed-rate alternative with the home equity loan calculator.

Sources & further reading

1What is a home equity line of credit (HELOC)? — Consumer Financial Protection Bureau
2What You Should Know About Home Equity Lines of Credit — Federal Reserve Board
3Bank Prime Loan Rate (WPRIME) — Federal Reserve Bank of St. Louis (FRED)

Is HELOC Interest Tax-Deductible on $100,000?

Sometimes — and the rule trips up more borrowers than the payment math does. Under current law, HELOC interest is only deductible if the funds are used to buy, build, or substantially improve the home securing the loan, per IRS Publication 936:

Use of funds	Interest deductible?	Example
Kitchen renovation, addition, new roof	Yes, if itemizing	Improves the home securing the debt
Debt consolidation (credit cards, other loans)	No	Doesn't improve the home, even though it's secured by it
Buying a second property or investment	No (on this home's HELOC)	Funds left the home the HELOC is secured against
Tuition, medical bills, general spending	No	Personal expense unrelated to the home

Deductibility also requires itemizing deductions rather than taking the standard deduction, and total mortgage debt (including the HELOC) must stay within IRS limits. Confirm your specific situation with a tax professional — this is general guidance, not tax advice.

The math changes the decision, not just the tax bill

If you're weighing a $100,000 HELOC for a renovation versus debt consolidation, the renovation use case gets a real tax subsidy on top of the lower rate typical of secured debt — often making it clearly the better math even before considering the value the renovation adds to the home. Consolidation loses that subsidy entirely, so compare the after-tax rate, not the sticker rate, against your existing debt.

Run the numbers

Home Equity Loan Payment Calculator

Compare the HELOC's variable payment against a fixed-rate home equity loan for the same $100,000.

Compare fixed vs. variable

How we researched this

Payment figures use Balance × (Rate ÷ 12) for interest-only and standard 240-month amortization for the repayment phase. Tax-deductibility guidance summarizes IRS Publication 936's home mortgage interest rules as of the 2026 tax year; rules can change and individual circumstances vary — this is not personalized tax advice.

$100,000 HELOC Payment: What It Costs at Every Rate (2026)

The Answer: $583–$833 Interest-Only, $775–$965 in Repayment

Qualifying for (and Surviving) a $100,000 Line

Is HELOC Interest Tax-Deductible on $100,000?

Frequently asked questions

Run the numbers yourself

Keep reading

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