How much can you AFFORD depends on what your budget it like, taking into consideration net income, debt payments, retirement contributions, utilities, food, gas, insurances, entertainment, etc. A mortgage lender will very rarely be able to tell you what you can afford unless they are also a budgeting planner.
What a mortgage lender can tell you is what you can QUALIFY for. Online mortgage calculators, bless their little digital hearts, only can give people a rough estimate of what one might qualify for. Their output is only as good as the information it asks for and the accuracy of the data that the user inputs. You use 5 different calculators, you will probably get 5 different answers, none of which will really matter since a mortgage lender is who you will need to talk to.
In theory, if you can qualify for X, then you can qualify for an amount less than X, but not necessarily for an amount more than X.