We live in a $400k home now. Want to move up to that next size house for my family of 5. How much money do you have to make a year to be able to afford a home around $800-$900 range???

First of all, I'm not sure why the next size house after a 400k one would be 900k. What about the houses in between? Second, since you are looking at twice the house then with out doing any calculations you can safely assume that yor payments will be at least twice what you are paying now, so if you are now paying $4000, expect to pay at least $8000. Now if you can afford that, I would assume it because you have a large savings account somewhere because of the extra $4000 a month you've been saving on your smaller mortgage right? Otherwise if you don't have any extra savings you are already spending too much regardless of your income. You'll only be able to afford a larger house if you cutback. Here are some calculators if you need further info: http://www.aboveallmortgage.com/calculators.php

here's a rough estimate; take the net selling price of your new home subtract your down payment (minimum 20% to avoid mortgage insurance) and divide the result by 3. example $800 home price - $200k down leaves $600k mortgage. $600k / 3 implies a gross income of $200k if you have other large payments your debt to income ratio will also affect your buying power.

You need 20% down and a fixed rate 15 year mortgage with a PITI not to exceed 25% of your net income.