$ Total household monthly pre-tax income
$ Current monthly rent or mortgage payment
$ Current household non-rent expenses/savings
$ Home purchase price portion to be financed
$ Home purchase price portion being paid upfront
Term of mortgage loan in years
% Annual percent rate of the mortgage interest
$ Monthly approximation of tax and HOA fees
$ Monthly approximation of total insurance
How Much House To Buy
Many factors go into determining how much house you can afford. There are general rules of thumb that say you can afford a mortgage of 3x - 4x your annual household income. Other, more advanced calculations would have you look at your debt-to-income ratio. Factor the potential costs of childcare, healthcare, or other major expenses. Then calculate the amount of mortgage you can afford based on these and other wide-ranging factors.
The bottomline is the amount of house you can afford depends on how much "free cash flow" you have to spend on housing each month. A good baseline to determine your monthly housing budget is by looking at your current rent or mortgage payment. If you are comfortable paying your current housing cost each month, then consider starting with this amount as a target for your new mortgage. You can also consider raising or lowering the amount for reasons that suit your unique cirumstances.