PITI is an acronym for Principal, Interest, Taxes, and Insurance. It refers to a person’s total monthly housing expense and is used to calculate their debt to income ratio. The higher the percentage of a person’s monthly housing expenses in relation to their gross income, the more risk there is associated with lending to them. A debt to income ratio is usually expressed as two numbers with the first number representing the percentage of income that goes towards PITI. The second number represents the percentage of income that goes towards PITI plus other recurring debts such as credit card payments, car loans, child support, and so forth.