How much can you afford?

It finds the highest price whose full monthly payment fits under both lending ratios, then rounds down to the nearest $1,000.

• Step one, your income. It divides your yearly household income by 12. Use gross income, before taxes.
• Step two, the two limits. The housing limit is 28 percent of that monthly income. The debt limit is 43 percent of it, minus your other monthly debts such as car payments, student loans, and credit card minimums. Whichever is lower is the most you can spend on housing each month.
• Step three, the payment. It works backward from that monthly number to a price, counting principal and interest on the loan, property tax, homeowners insurance, and HOA dues. Your down payment is added on top of the loan.

With the starting numbers, $150,000 a year is $12,500 a month. The housing limit is $3,500 and the debt limit is $4,875, so housing sets the limit. With $60,000 down at 6.5 percent over 30 years, that buys a home of about $529,000, with a monthly payment just under $3,500.

The calculator does not add mortgage insurance. If you put less than 20 percent down on a conventional loan, or use an FHA loan, your real limit will be somewhat lower. The mortgage calculator shows a payment with mortgage insurance included.

Your rate, your other debts, and the costs that come with the home: HOA dues, insurance, and property tax.

• HOA dues. Most Las Vegas neighborhoods have an HOA, and many master-planned communities have two: a master association and a neighborhood one. Every $100 a month in dues lowers your price range by roughly $15,000 at today's example rate. Check the dues on each listing.
• Property tax. Nevada's property tax is low compared with most states. The calculator uses 0.6 percent of the price a year as an estimate. Your real bill comes from the assessor's taxable value, not your price, and a home with a SID or LID assessment carries an extra charge on the bill.
• Insurance. The starting number is $2,000 a year. Many Las Vegas homes insure for less, while larger homes, older roofs, and pools cost more. Get a quote on the actual address.
• Your rate. A point of interest rate moves your range by tens of thousands of dollars. The rate here is an example; a lender gives you the real one.
• The ratios themselves. 28 and 43 percent are a conservative rule of thumb. Fannie Mae allows a total debt ratio up to 50 percent on loans approved through its automated system, and FHA and VA loans have their own rules. A higher approval is not always a comfortable payment.