If you search the web for “financial calculator,” you’ll find hundreds of sites. Many of them present calculators borrowed from other sites, some present calculators that are at best difficult to use and at worst inaccurate. Then there are a few sites that offer simple, powerful calculators. Here are my favorite calculator sites.
General Financial Calculator Sites
Several sites offer a wide range of calculators. Only a few sites do many different calculators well. Here are my top picks if you want to find a lot of options quickly:
Dinkytown: Stupid name, great site. I frequently use their tax calculator. I haven’t found their debt calculators easy to use, but I love everything else. Go here for retirement, loan, auto loan, savings, small business, and investment calculators.
Bankrate: In addition to helpful articles and advice, Bankrate offers a powerful suite of financial calculators. Use their tools to budget, compare mortgage rates from actual banks, run retirement calculations, and determine your taxes. You can even calculate your lunch savings if you’re not sure you can really save money by brown-bagging it.
CNNMoney: The venerable financial magazine offers a wide range of financial tools and calculators. Their options are centered around four primary areas: retirement, investing, real estate, and financial planning. I particularly like the Ideal Budget tool which tells me the percentage of my budget each spending area accounts for.
I rely on two sites for most of my mortgage calculators. I’ve found these to be the most reliable in my calculations.
Mortgage Professor: Find out everything you ever wanted to know about mortgages, and run through every conceivable mortgage scenario you can think of. His robust mortgage calculators are simply the best I’ve found. In his home affordability calculator, you’re asked to input the price, and then he calculates how much you have to earn to afford it.
Bankrate: Bankrate also offers powerful mortgage calculators. Unlike those at Mortgage Professor, their home affordability calculator doesn’t make you choose a prospective home price first. Instead it tells you how much you can afford.
John Laing Homes: Yes, it’s from a home builder, but the calculator is comprehensive. Once you’ve determined your likely monthly payment, go to Wish List > Loan Amount Tool to enter your income, housing costs, and all other monthly expenses to see whether you can really afford it.
I used several different calculators while creating my debt payoff plan. You can find debt calculators all over the web.
Mvelopes: This is my favorite debt calculator. You can enter as many debts as you have, with interest rates and monthly payments. Then you can play with different additional monthly payments. In addition to giving you the best payoff plan, it shows you principal and interest for each monthly payment until the predicted payoff date.
Two sites offer the best tax calculators around. One might surprise you.
IRS: The IRS withholding calculator is actually pretty cool. It really only works at the beginning of the year, though. As bonuses or raises roll in, it becomes less reliable. Use it to figure your withholding at the beginning of the year.
Dinkytown: As the year progresses, you get a more accurate tax prediction at Dinkytown. They also offer a wider range of calculators than the IRS.
Of course, no calculator is 100% accurate, but these will give you a picture of what you can reasonably expect. And, of course, they’re free, so you can run calculations as often as you want.