Definitions:

Loan Amount: The amount you borrow at the start
Or the amount you can borrow given a certain interest rate and specified fixed monthly payment.

Interest Rate: The annual interest rate of the loan in percent.

Period: The length of the loan in either years or months.

Monthly Payment: The amount you will have to pay each month for a given loan amount, term, and interest rate. Excludes taxes and property insurance (and mortgage insurance).

You can get a rough estimate of PITI (including taxes and insurance) by increasing the interest rate by the tax rate (about 2.4%) plus the property insurance premium (about 0.7%). So, add 3.1% to the interest rate as a cheat.