A good rule of thumb is that your total mortgage should be no more than 28% of your pre-tax monthly income. You can find this by multiplying your income by 28, then dividing that by 100.
For example, let’s say your pre-tax monthly income is $5,000. Your maximum monthly mortgage payment would then be $1,400: $5,000 x 28 = $140,000. $140,000 ÷ 100 = $1,400