Tools41.8781° N 87.6298° W · CHICAGO, ILRun the numbers the way the underwriter willEach tool applies the actual rule, cites it, and tells you which lever moves the result.Underwriting mechanics · all five statesFHA Self-Sufficiency TestFor three- and four-unit purchases. Does 75% of the appraiser's market rent cover the whole PITI, mortgage insurance and dues included?