How Much Can You Actually Borrow Against Your Home? A Walkthrough with Real Numbers
Lenders say 80-85% CLTV. Here's what that actually means in dollars, with a working example you can plug your own numbers into in about two minutes.
“How much can I borrow?” is the first question most homeowners ask. The answer is almost always some version of “it depends on your LTV.” That’s useless if nobody explains what an LTV actually is, so let’s walk through it.
By the end of this post you’ll be able to look at your mortgage statement and estimate your maximum HELOC or home equity loan amount in your head.
The three numbers that matter
- Your home’s value — what it would sell for today.
- Your mortgage balance — what you still owe.
- The lender’s CLTV cap — usually 80%, sometimes 85% or 90% for well-qualified borrowers.
CLTV stands for Combined Loan-to-Value. It’s the total of all the loans against your home, divided by its value. A lender who caps CLTV at 80% is saying, “all mortgages and credit lines on your house, combined, can’t exceed 80% of what it’s worth.”
A worked example
Meet Sarah. She bought her home in 2019 for $340,000. Today, a comparable house up the street just sold for $520,000, so let’s call her home value $520,000. Her current mortgage balance is $245,000.
Step 1: Figure out the CLTV cap in dollars. $520,000 × 80% = $416,000
This is the maximum total debt the lender will allow against her home.
Step 2: Subtract what she already owes. $416,000 − $245,000 = $171,000
That $171,000 is her theoretical maximum HELOC or home equity loan amount at this lender’s 80% cap.
Step 3: Check what happens at a different CLTV cap. If the lender offered 85% CLTV instead: $520,000 × 85% = $442,000 $442,000 − $245,000 = $197,000
That extra 5% of CLTV is worth $26,000 to Sarah. Shopping around matters.
Why your number will probably be lower than the “max”
The CLTV cap is the ceiling, not the offer. Lenders then apply their real underwriting:
- Credit score. Under 700 and your max usually drops, or the rate jumps enough to feel like a drop.
- Debt-to-income ratio. If your total monthly debt payments would exceed ~43-45% of your gross monthly income, they’ll offer less — or nothing.
- Income stability. Self-employed, recent job change, or variable commission income often means a smaller approval, even with great credit.
- Property type. Condos, second homes, and investment properties frequently get a lower CLTV cap (70-75%).
In Sarah’s case, if her credit is 740 and her debt-to-income is clean, she’ll probably get close to that full $171,000. If her score is 670 and she already carries $15,000 in credit card balances, the same lender might cap her at $110,000 or less.
The appraisal question
Notice we used $520,000 as Sarah’s home value because “the house up the street sold for that.” In the real world, the lender’s appraiser decides what your home is worth, not you, not Zillow.
Appraisals typically come in within 5-10% of what you expected, but they can surprise you either direction. If the appraisal comes in low, your borrowing limit comes with it. If your home office renovation added value on paper but the appraiser doesn’t count it (because it removed a bedroom), that affects you too.
Two things you can control:
- Clean and declutter before the appraiser visits. It sounds silly but condition biases humans.
- Share recent comps. If you know of three similar homes in your neighborhood that sold in the last 90 days, put a simple list on the kitchen counter.
The shortcut math to use in your head
Want a rough estimate without opening a spreadsheet?
Home value × 0.80, minus your mortgage balance, is your starting ballpark.
So if your home is worth ~$450,000 and you owe ~$200,000: 450 × 0.8 = 360. 360 − 200 = $160,000 ish.
That number will land within about 10% of what a lender actually offers a well-qualified borrower. If you’re under 700 credit or your DTI is tight, mentally chop 20-30% off.
A few quick reality checks
- You rarely want to borrow the max. Just because you can pull out $171,000 doesn’t mean you should. More debt is more risk, and your home is the collateral.
- HELOC limits are usually higher than home equity loan limits at the same lender. Not always, but common.
- Some lenders quietly use 75% CLTV even though their marketing says 80%. Read the fine print before a hard credit pull.
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