The 28/36 rule is a good rule of thumb to determine how much house you can afford. It states that you shouldn't spend more than 28% of your gross monthly income on home-related costs and no more than 36% on total debts, including your mortgage and other loans. To determine if a house is affordable based on your salary, you can calculate your total housing expenses, including principal, interest, mortgage insurance, property taxes, and homeowner's association fees. This total can then be divided by your gross monthly income to determine the percentage of income that would go towards housing expenses.