There are several great fitness calculators available online, many of which can be accessed right here on That's Fit. Some can provide you with a fairly accurate estimation of your BMI, while others can approximate how many calories you burned performing a particular exercise in a given amount of time. Hell, there are even some that can determine if you are overstressed (although you probably don't need a calculator for that one in the first place).

One of my favorite calculator tool helps determine what your One Rep Max will likely be on an exercise. For example, if you can bench press 225 pounds for 5 reps, then your estimated 1RM is 253 pounds. Is it accurate? Maybe not precisely, but it's probably pretty close. This same calculator can also be used to quickly figure out a certain percentage of your 1RM. So, if your 1RM is 253 pounds, then 50-percent of that is 127 pounds. Granted, you could have easily figured that one out in your head, but what if you wanted to know what 65-percent of your 1RM is? Not so easy that time, is it, Einstein?

Knowing what your One Rep Max is on an exercise is an important part of designing the right resistance training program for yourself. It will help ensure that the weight you are lifting is neither too heavy -- leading to the increased risk of injury, nor too light -- causing workouts to be less effective than they potentially could be.

Interested in knowing what your 1RM might be? If so, click HERE.