The Internet is crawling with smart money sites offering calculators, data and advice. Below, TIP SHEET reviews some standouts that can help you make good financial choices.

Analyzenow.com: A former engineer breaks down all the math behind retirement planning. It includes free Excel spreadsheets, book suggestions, articles and a “tough love” approach to building post-job budgets—just the brutal facts, according to its author.

Retailmenot.com: Easy, comprehensive couponing, with discount codes for just about every online and retail store. Also includes user reports, so you don’t get stuck using bad codes. Check this site before you click “place order” and you’ll save money.

Hsh.com/usnrcalc.html: Should you refinance? This calculator will tell you, in dollars and cents. Use it to compare total costs of the loan you have now with the one you think you want.

Taxadmin.org: Everything you need to know about state taxes, like how much you can save by moving. Use it to plan your retirement to a low-tax state, or vacations to states with sales-tax holidays.

Pfadvice.com: Money-saving tips on everyday expenses like pets, groceries and gardens. Users challenge each other to share their best tips; you might pick up some gems.