HELOC & Home Equity Loan Calculator

A Home Equity Line of Credit (HELOC) is a revolving credit line secured by your home, similar to a credit card except backed by the value of your house instead of just your promise to pay. You can draw, repay, and re-draw during a fixed "draw period", and some plans let you pay only the interest on the outstanding balance. After the draw period ends you can no longer borrow, and you enter a "repayment period" — the CFPB says often ten or 15 years — or, on some plans, owe the whole balance at once as a balloon payment. Unlike a cash-out refinance, a HELOC is a second mortgage — your first mortgage stays untouched. This makes HELOCs especially attractive when your existing mortgage is at a much lower rate than current refinance rates would be (the position of US homeowners who locked in sub-3% mortgages around January 2021, when Freddie Mac's 30-year average hit a record low of 2.65%).

The LTV math that determines your borrowing limit

Lenders cap the combined Loan-to-Value (CLTV) — your first mortgage plus the HELOC — as a percentage of home value; the cap is lender policy rather than regulation, and it differs between lenders. A home worth $600K with a $350K first mortgage and an 85% CLTV cap means total allowable debt is $510K, leaving $160K of available HELOC. The lower the cap, the safer the loan for the lender — and the smaller your line. A lender may also price a lower-CLTV line more cheaply, because the equity cushion protecting it is larger, so ask for quotes at more than one line size.

The other gotcha: lenders re-evaluate home value during the draw period. In a sharp housing downturn, lenders can "freeze" or even reduce your credit line if they think your equity cushion has eroded. Regulation Z (12 CFR §1026.40(f)(3)(vi)) expressly permits this when the home's value "declines significantly below the dwelling's appraised value", or when the lender reasonably believes you can no longer meet the payments because your circumstances have materially changed. The credit line is a promise, not a guarantee — and a downturn can break the promise at the worst possible time.

The ASEAN angle — equity loans look different in APAC

Across Singapore, Malaysia, Indonesia, the Philippines, Thailand and Vietnam, borrowing against a home more often takes the form of a term loan secured on the property — a lump sum repaid on a schedule — or an overdraft secured on it, than the US draw-period-then-repayment line this tool models. Products, names and rules differ by bank and country, and in Singapore a property-secured loan sits inside MAS's debt-servicing rules, so ask the bank which form it offers and how it is assessed. A term loan is closer to the repayment half of this calculator: set the draw period to the shortest the field allows and read the repayment row. For Singapore retirees with an HDB flat, the HDB Lease Buyback Scheme is a different route to the same equity — it sells part of the remaining lease back to HDB rather than borrowing against it.

A HELOC is a credit card backed by your house. Used for high-ROI purposes — home improvement, education, debt consolidation — it's one of the cheapest sources of long-term capital. Used carelessly, it's the fastest path to losing your home.

When HELOC beats cash-out refinance — and when it doesn't

HELOC wins when your existing mortgage rate is significantly lower than current refinance rates. If you locked a 3% mortgage in 2021 and current rates are 7%, refinancing the full mortgage to extract equity means re-financing the whole balance at 7% — far more expensive than carrying the original mortgage and adding a smaller HELOC at 8%. The math: $400K at 3% over 30 years costs $1,686.42 a month; refinancing $500K (including $100K cash-out) at 7% costs $3,326.51 a month — vs keeping the original mortgage ($1,686.42) and adding a $100K HELOC at 8.5% ($867.82 a month once it amortises over 20 years) for a combined $2,554.24. The HELOC route costs $772.27 a month less even at the higher HELOC rate, and while the line is interest-only the pair costs $2,394.75. The HELOC's rate can move, though; the refinance's would not. Cash-out refi wins when (a) you need more cash than the lender's per-line ceiling allows, (b) you want a fixed rate (HELOCs are variable), or (c) your existing mortgage rate is close to current rates anyway.

Common HELOC use cases — ranked by financial sense

Home improvement — usually the best use. Adds value back to the property securing the loan, and the interest may be tax-deductible in the US: under IRS Publication 936 (2025 returns) the loan must be used to "buy, build, or substantially improve" the home that secures it, and it counts toward the USD 750,000 acquisition-debt cap (USD 375,000 married filing separately). Debt consolidation — strong case when moving high-rate credit-card balances onto a line priced at a fraction of the card rate, but only if the borrower changes the spending behaviour that created the debt; otherwise the cards refill and the home is now collateral for the original problem. Education funding — defensible but federal student loans are often cheaper and have better deferral options. Business capital — high-risk; putting personal residence at stake for business venture is rarely the optimal capital stack. Investment portfolio leverage — controversial; some sophisticated investors do this, but margin calls during downturns mean potential forced selling at the worst time. Vacation, wedding, luxury consumption — almost never makes sense; you're borrowing against your home to pay for a depreciating experience.

The variable-rate risk most borrowers underestimate

HELOC rates are indexed — usually to the US prime rate — plus a lender margin. Prime stood at 7.00% on the Federal Reserve's H.15 release of 16 October 2026, having risen from 6.75% on 17 September 2026; it sat at 8.50% from 27 July 2023 to 18 September 2024 and at 3.25% from 16 March 2020 to 16 March 2022 (Federal Reserve H.15; FRED series DPRIME). How quickly a change reaches your rate is set by your agreement; there is no rate-lock on a variable line. A borrower who drew at prime + 1% in early 2022, when prime was 3.25%, was paying 9.50% on the same balance in August 2023 — more than double the interest cost. Build a buffer: the stress field above shows the payments at a higher rate before you draw. Some lenders offer "fixed-rate conversion" features that let you lock a portion of the balance at a fixed rate — useful if you want predictability on a large draw.