CLTV Ratio. A ratio that indicates the risk of a homeowner going into default if a home purchase is funded by multiple mortgages. It is calculated by dividing the total value of the combined mortgages by the value of the property. High values (75-85%) are usually required by creditors before they extend a second mortgage or refinancing option to a homeowner, although lower values indicate that there is less risk of default (the loan value is a smaller percentage of the overall home value).