Loan-to-Value Ratio (LTV)

A loan-to-value ratio is the amount owed on a secured loan divided by the value of the asset securing it. Lenders use it as the collateral half of underwriting, alongside the debt-to-income ratio, which is the capacity half. Put $40,000 down on a $400,000 house and the $360,000 loan is a 90 percent loan-to-value ratio, which is the same fact as a 10 percent down payment. No statute defines the ratio itself, but federal law defines the values several rules divide by, most notably the "original value" the Homeowners Protection Act uses for mortgage insurance cancellation (12 USC 4901(12)).

A related term causes most of the confusion. The plain loan-to-value ratio counts only the first mortgage, while the combined loan-to-value ratio adds every lien secured by the property. A lender that will lend to 85 percent combined loan-to-value is talking about the total of all liens, not about the new loan alone.

The interesting question is never the numerator. It is what the lender divides by, because the same property has several defensible values and the rules do not agree on which one to use.

On a purchase, the denominator is the lower of the contract price and the appraised value. That single convention has one consequence worth planning for. If the appraisal lands below the agreed price, the lender sizes the loan against the appraisal, so the ratio rises and the gap has to be closed with cash, a renegotiation, or an exit under an appraisal contingency. Nothing about the purchase price changed.

On a refinance, the denominator is a fresh appraisal. This is the one route by which rising prices help, and it is written into the statute: for a refinance of the borrower's principal residence, "original value" means the appraised value the lender relied on to approve the refinance (12 USC 4901(12)).

For mortgage insurance cancellation, the denominator is frozen. The Homeowners Protection Act measures against the value at origination rather than against a current appraisal, which is why appreciation alone does not retire private mortgage insurance on the loan you already have.

Several thresholds sit on the same scale, and holding them as one list is more useful than meeting them one page at a time.

Two of those behave differently under prepayment, which is worth knowing before paying a mortgage down for the purpose. Extra principal brings the 80 percent request forward, because the borrower may elect to have that date measured on actual payments. It does nothing at all for the 78 percent automatic termination, which follows the initial schedule "irrespective of the outstanding balance" (12 USC 4901(18)).

The ratio is also how negative equity gets described. On an auto loan the collateral usually depreciates faster than the balance amortizes, so a loan that starts near 100 percent of the vehicle's value can spend its early years above it. That is the same measurement applied to a different asset, and it is why a long term on a depreciating asset behaves so unlike a long term on a house.

Divide what is owed by the value the lender is using, and read the answer against whatever threshold the program applies. On a purchase the value is the lower of price and appraisal; on a refinance it is the new appraisal; on a vehicle it is a valuation guide the lender selects.

A hypothetical example, and the point of it is that the price never moves. Hana agrees to buy a house for $400,000 and plans to put $40,000 down, which needs a $360,000 loan. On the contract price that would be a 90 percent ratio ($360,000 divided by $400,000). The appraisal comes back at $385,000, so the lender divides by the lower figure instead, and the ratio is 93.5 percent ($360,000 divided by $385,000). She has crossed the 90 percent line, which on a conventional loan generally raises what mortgage insurance costs and on an FHA loan decides whether the annual premium ever ends at all.

Getting back to 90 percent against the appraised value means borrowing no more than $346,500 ($385,000 multiplied by 0.90), which requires a down payment of $53,500 rather than $40,000. The extra $13,500 buys no more house. It buys a different ratio.

Pros

• It states the lender's actual risk in one number, which is why it drives pricing, mortgage insurance, and program eligibility more directly than the down payment does.
• A lower ratio generally means a lower rate, no mortgage insurance above the 80 percent line on a conventional loan, and more room to sell or refinance without being short at closing.
• It is comparable across loan types and across assets, so it is the honest way to compare a 3 percent conventional loan against a 3.5 percent FHA loan against a nothing-down VA loan.

Cons

• It is only as reliable as the valuation underneath it, and on a purchase the borrower does not control the appraisal.
• Chasing a low ratio with every available dollar can leave a household owning a house with no cash reserve, which is how a broken furnace becomes credit card debt.
• The thresholds use different denominators, so a borrower who has "reached 20 percent equity" by market appreciation may still owe mortgage insurance.
• On a depreciating asset the ratio can worsen while the borrower pays perfectly on time.