Irish Calculators
Loans & mortgages

Mortgage Loan-to-Value Ratio Calculator

Compare the primary mortgage and any other property-secured debt with the value you enter. This is a property-finance ratio, not a valuation, a credit limit or customer lifetime value.

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Your numbers

Your figures stay on this device.

How the calculation works

Loan-to-value compares property-secured borrowing with the value supplied for that property. This version combines the primary mortgage with other secured debt, making the relationship between borrowing, value and remaining equity explicit.

Combined LTV = (primary mortgage + other included secured debt) / supplied property value × 100.

  1. Identify all included secured debt

    Add the primary mortgage balance and the additional secured borrowing. Use outstanding principal figures corresponding to the same point in time.

  2. Express debt as a share of value

    Divide total secured debt by property value and multiply by one hundred. The denominator remains the full property value, not the deposit or the equity.

  3. Read the equity alongside LTV

    Subtract the same total debt from property value. This gives equity before sale costs and provides a monetary counterpart to the percentage.

Worked example: Eighty percent mortgage

Sample inputs demonstrate the method. They are not a forecast or product offer.

The example divides a €160,000 mortgage by a €200,000 property value. With no additional secured debt, combined LTV is 80%. Subtracting the same €160,000 from the value leaves €40,000 equity before sale costs.

Property value or agreed price
200000
Primary mortgage balance
160000
Other debt secured on this property
0

Expected result

Combined loan-to-value
80%
Equity before sale costs
€40,000.00
Worked example: Combined debt above property value

Sample inputs demonstrate the method. They are not a forecast or product offer.

Property value or agreed price
100000
Primary mortgage balance
100000
Other debt secured on this property
10000

Expected result

Combined loan-to-value
110%
Equity before sale costs
-€10,000.00

Understanding your result

An LTV above 100% means the included debt exceeds the value entered. The resulting equity is negative; the tool deliberately displays that position rather than capping the ratio.

A lower ratio can result from repaying debt, increasing the assumed value, or both. Only the first necessarily reflects a cash repayment; changing a valuation assumption does not release money.

Questions you might have

Can LTV exceed 100%?

Yes. It means the included secured debt exceeds the value you entered, producing negative equity.

Choosing the right inputs

Property value or agreed price
Use a positive property value or agreed price on a stated date. When comparing scenarios, keep the valuation basis consistent; the tool does not obtain a bank valuation.
Other debt secured on this property
Include additional borrowing secured on this property. Leave unrelated unsecured debts out of the LTV calculation and avoid repeating a balance already included in the primary mortgage.

Common mistakes to avoid

  • Do not use the monthly mortgage repayment in a field asking for a balance.
  • No lending ceiling or eligibility decision is applied, and sale or settlement costs are not deducted from the displayed equity.

Assumptions to check

  • The property value is supplied by you; the calculator does not perform a valuation or apply lender limits.

Sources and method

Read our calculation and testing approach.