The short answer is that you will usually need at least 5% down on a conventional mortgage. You can get an FHA mortgage with as little as 3.5% down. VA or USDA loans are available with no money down at all. Something to consider though is how your down payment will affect your monthly house payment. How much you put down will certainly affect how much your monthly principal payment will be. It will also largely determine whether you have to pay private mortgage insurance or “PMI”.