Combined Loan-to-Value Calculator

Combined LTV is what second-mortgage lenders actually care about. A 200,000 first mortgage plus a 40,000 home equity line on a 300,000 property = 80% combined LTV. Above 80-85% combined LTV, most lenders stop offering new second loans. Knowing your combined LTV is the first step before shopping for home equity financing.

Run it with sensible defaults

Using first mortgage balance of 200,000, second loan / heloc balance of 40,000, property value of 300,000, the calculation works out to 80.00%. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — First Mortgage Balance, Second Loan / HELOC Balance, and Property Value — do not pull with equal force. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.

How the math works

Combined loan balances divided by property value. Standard second-mortgage underwriting metric.

Stress-testing against property value

Combined LTV is more sensitive to property value than to debt balances. The same loans against a property valued 10% lower move the ratio up by several percentage points; the same loans against a property valued 10% higher pull the ratio down by the equivalent. Running the calculation at a more conservative property value — what an honest valuation in a soft market might produce — shows how close the ratio sits to lender thresholds before any new debt is added.

What this snapshot doesn't capture

The ratio reflects balances and property value as entered. It does not adjust for accrued interest between statement dates, undrawn capacity on a home equity line that may later be drawn, or for property value moving between the last valuation and today. The figure is a point-in-time snapshot rather than a tracking metric.

Worked example

A property owner has a first mortgage balance of 250,000 on a home valued at 400,000. They also carry a home equity line of credit with a current balance of 60,000. The combined LTV calculates as:

(250,000 + 60,000) ÷ 400,000 = 77.5%

This combined LTV of 77.5% sits below the typical lending ceiling for new second-mortgage products. If the property value falls to 380,000 while both loan balances remain unchanged, the combined LTV rises to 81.6%, potentially affecting availability of additional credit or terms offered by lenders.

When this metric matters

• Assessing eligibility for a new second loan or home equity product
• Understanding how property value changes affect borrowing capacity
• Comparing multiple scenarios before committing to additional secured debt
• Monitoring risk exposure when property markets fluctuate
• Planning debt consolidation or refinance structures across multiple loans

What the result shows

Combined LTV expresses, as a percentage, how much of your property's value is committed to repay all secured debt. A result of 75% means that three-quarters of the property serves as collateral for mortgages and other loans. It does not account for equity cushion (the gap between combined debt and property value that protects a lender in default scenarios), nor does it address individual loan terms, interest rates, or monthly payment capacity.

What the result does not capture

Combined LTV ignores the structure and pricing of each loan separately. Two properties with identical 75% combined LTV may carry very different risk profiles if one has a first mortgage at a fixed rate and a second loan at a floating rate, while the other has the opposite. The metric also omits property-specific factors such as condition, location, and market liquidity, all of which lenders weigh during underwriting.

Educational illustration

This calculator models combined loan-to-value for illustration purposes. The result shows a mathematical relationship between total secured debt and property value as entered. It does not account for individual lender policies, eligibility criteria, or real-world application outcomes. Actual approval thresholds and figures vary by lender and underwriting assessment.