Most banks use the 28/36 rule to figure out how much your house payments should be.
This means your monthly costs to service your housing payment should not be more than 28% of your gross income and the total of all your debt payments should not be more than 36% of your gross income.
A general rule of thumb to get how much house you can afford is to multiply your annual salary by 3.5.
In your case with a salary of $90000 you should be looking at houses in the $315,000 range.
Assuming you make a down payment of 20% (recommended)
you will still need to borrow about $252,000.
Assuming an interest rate of 4.75% and an amortization of 25 years this works out to about $1,429.99 per month in mortgage costs.
Your pre tax income per month is $7500.
This means you will need about 19% of your pre tax income to service your mortgage costs alone.
Factor in property taxes,
insurance and utilities and this percentage will obviously climb and challenge that 28% that banks look at but this calculation is close to what you can expect in the real world.
Good luck with your home purchase and make sure you save 20% down.
If you only save 5% the bank will force you to take out an insurance policy on the debt increasing your monthly costs by a couple hundred dollars per month.