- LTV measures the lender’s exposure, not yours: it is what you owe over what the home is worth.
- Combined LTV counts every balance secured against the title, and it is the figure that governs additional borrowing.
- You get under a threshold in exactly two ways — repay principal, or the home appreciates. Both are shown here.
- Which LTV line applies to you is a lender-and-program question; set the threshold in this calculator to the one you have actually been quoted.
How loan-to-value works
Loan-to-value is one division: what you owe against the home, over what the home is worth. At $480,000 owed on a $750,000 home the LTV is 64%, and the other 36% — $270,000 — is your equity.
It is the single most important number a lender looks at after your income, because it measures their exposure rather than yours. The lower the LTV, the more the home would have to fall in value before the loan is undersecured, and that is what LTV thresholds exist to manage.
Two LTVs matter, not one. The plain LTV counts only the first mortgage. The combined LTV counts every balance secured against the home — a second mortgage, a home equity line of credit, anything recorded against the title — and it is the number that governs whether you can borrow more.
The math
LTV is the mortgage balance divided by the home value, times 100. Combined LTV is the same division with every secured balance in the numerator. Equity is the value minus every secured balance, and the equity share is that figure as a percentage of value — so LTV and equity share always sum to 100% when there is only one loan.
The threshold rows work backwards from the same identity. The balance that sits exactly at a given LTV is value × threshold; the room left is that ceiling minus what you already owe. When you are above the line, the two ways down are stated separately because they are genuinely different actions: the paydown is what you would have to repay, and the value figure is what the home would have to be worth for the same balance to clear the line.
The thresholds are inputs and this page states none of its own. Which LTV line applies to you, and what happens at it, is a lender-and-program question that changes without notice — a calculator that hardcoded one would be making a claim it cannot keep verified.
Worked example
A $750,000 home with a $480,000 mortgage and nothing else recorded against it: LTV 64%, combined LTV 64%, equity $270,000, equity share 36%. At an 80% threshold the ceiling is $600,000, so there is $120,000 of room. At a 65% threshold the ceiling is $487,500 — only $7,500 of room, which is the practical difference between the two lines on this home.
Now raise the balance to $640,000 and nothing else changes. LTV becomes 85.3%, above the 80% line. Getting under it takes either a $40,000 paydown or a home worth $800,000 — the same gap, expressed the two ways it can actually be closed.
Key terms
- Loan-to-value (LTV)
- The mortgage balance as a percentage of the home’s value. Falls as you repay principal and as the home appreciates.
- Combined loan-to-value (CLTV)
- Every balance secured against the home, as a percentage of its value. A home equity line counts here even if you have not drawn on it beyond the balance shown.
- Equity
- The home’s value minus everything secured against it — the amount that would be yours if it sold at that value with no other costs.
- Appraised value
- The value a lender will actually use, which is not necessarily what you paid or what a listing site estimates. LTV computed from an optimistic value is optimistic in the same proportion.