Your home equity is simple to calculate: market value minus everything you owe against the property. A $500,000 home with a $300,000 mortgage means $200,000 of equity. But if you try to borrow against it, you will quickly discover that lenders will not hand you anywhere near $200,000. The number that matters is accessible equity — and it is always smaller than total equity.
Why Total Equity Isn't Borrowable Equity
Lenders limit borrowing against a home using loan-to-value (LTV) caps: the maximum share of the home's value that all loans against it can add up to after the new borrowing. These caps exist to protect the lender — if values dip or the loan defaults, the cushion between what is owed and what the home is worth absorbs the loss.
Common underwriting caps (these are typical industry limits, not offers, and individual programs vary) look roughly like this:
- First liens (e.g., a cash-out refinance): often capped around 80% LTV for a primary residence, sometimes lower for investment properties.
- Second liens (home equity loans and HELOCs): some lenders allow combined LTV up to roughly 85-90%, since the pricing reflects the added risk.
Run the math on that $500,000 home with a $300,000 balance. Total equity is $200,000. But at an 80% cap, total lending against the home tops out at $400,000 — so the accessible slice is about $100,000, half the equity you "have." At a 90% combined-LTV cap on a second lien, roughly $150,000 might be reachable. The last 10-20% of your home's value is essentially locked: yours on paper, but touchable only by selling.
Your credit profile, income, and debt-to-income ratio must also support the new payment — an LTV cap is the ceiling, not an entitlement.
Three Ways to Tap It
The main restructuring options reach the same equity through different doors:
Cash-out refinance. Replaces your existing mortgage with a larger one and hands you the difference in cash. You end up with a single loan and a single payment — but at today's rate on the entire balance. This tends to make sense when the new rate is comparable to or better than your current one; it is expensive if it means giving up a low rate on a big balance. Closing costs run like a full mortgage.
Home equity loan (HEL). A second, separate loan behind your existing mortgage, delivered as a lump sum with (typically) a fixed rate and fixed payments. Your first mortgage is untouched — which is exactly what you want when your existing rate is worth keeping. Best suited to a known, one-time need.
HELOC. A revolving line of credit secured by the home. You draw what you need, when you need it, and pay interest only on what is outstanding — usually at a variable rate. Ideal for staged expenses (a phased renovation) or standby flexibility, but the variable rate and the temptation of an open line are real risks, and each future draw restarts part of your payoff math.
Choosing Between Them
The decision usually hinges on two questions: Is your current first-mortgage rate worth protecting? (If yes, second liens beat a cash-out refi.) And is the need lump-sum or ongoing? (Lump sum favors a HEL or refi; staged spending favors a HELOC.)
Because the answer depends on your existing rate, balance, timeline, and how much accessible equity the caps actually leave you, it is worth modeling rather than guessing. The free Shouldirefi Analysis Tool estimates your accessible equity under common LTV caps and compares the long-run cost of each option side by side, and the free Financial Audit at /tool/audit shows where your current LTV stands today.
All figures are estimates for informational purposes only — not financial advice. Consult a qualified professional before making financial decisions.