Rent is a major factor in determining a person's debt to income ratio. The debt to income ratio is a measure of a person's ability to pay back debts and is calculated by dividing the total amount of debt owed by the total amount of income earned. Rent is generally not included in the debt to income ratio calculation because it is not considered a debt. However, it is important to remember that rent can have a significant impact on a person's ability to pay back debts. Thus, although rent is not included in the debt to income ratio calculation, it should still be taken into account when considering a person's overall financial situation.