There is no single right share. A lower share leaves more room for savings and unexpected costs, while a higher share leaves less. Choose the share that still leaves room for your other goals.

No. Car loans, student loans, and card payments are not subtracted here. Subtract them from your budget before you choose a price.

Lenders usually look at gross income, which is income before tax. Use your gross figure, then leave room for the taxes you actually pay.

A larger down payment means a smaller loan for the same price, so the monthly payment falls. That leaves more of the budget for a higher price.

It lowers the monthly payment for a given loan, so it raises the price that fits the budget. It also adds interest over the life of the loan.