Online mortgage calculators are a popular and somewhat useful way to compare different types of mortgage loans in the comfort of your own home. Calculators assist in doing complex and difficult calculations that may be related to mortgages. It is this complexity that makes calculators popular, but can also make them inaccurate. Calculators are still useful if you keep some basic facts in mind while using them for your mortgage calculations.

When dealing with certain mortgage types, no calculator can ever be completely inaccurate. This is true of hybrid and adjustable rate mortgages (ARMs), because these types of loans will fluctuate in the future depending on prevailing interest rates at the time. For this reason, calculators can only accurately calculate the initial, fixed rate period on these loans. Other calculations are often based on a “worst-case scenario”. While this can be helpful in informing you of the risks associated with these loans, it is of little help in determining exact repayment charges.

Another problem with mortgage calculators is that the calculations often deal in basics and don’t take some factors into account. You may find yourself asking if the calculator has included insurance, property taxes, or other factors in calculating your payments.

One simple way to determine what the mortgage calculator has actually taken into account is to look at the questions it asks you. The more questions asked, the more accurate the information you receive will probably be. By including more information in its calculations, the mortgage calculator will usually arrive at a more realistic number.

Also, make sure to read the small print. Often calculators are accompanied by very fine print to the effect that the mortgage calculator company cannot be held responsible for any misinformation received through incorrect calculations. These disclaimers are there mainly to relieve the company of legal liability, but could also indicate that the calculator’s source is not particularly confident of its accuracy.