The this calculator should be used if your body fat % is less then 12% or you can see a 4 pack. If neither one of these applies to you, use the other calculators listed.

For males just starting their fitness journy and are not yet lean or strong.

For females just starting their fitness journy and are not yet lean or strong.

Your scale weight can vary wildly from day to day based on the amount of salt you have consumed and other factors, don’t panic if your weight plummets one day then seems to be stalled or even increase the next – stay your course! If you do your eat as directed here and perform the amount of exercise you have set for "Activity Level", then you will lose fat! To measure your progress, take your weight at the same time every day and measure your bodyfat. Measuring your bodyfat is very important to do if you are weight lifting in addition to losing fat because if you are gaining muscle and losing fat at the same time, the scale alone wont indicate your progress.

Basal Metabolic Rate (BMR) is what calorie calculators estimate. BMR is basically the rate your burns calories when resting. The gold standard for measuring BMR is a medical laboratory test where they measure the concentration of oxygen and carbon dioxide in your inhalation and your exhalation as well as the precise rate of breathing (liters per minute). From this they can calculate the rate at which oxygen is being converted into carbon dioxide, in other words, how fast your body is burning calories. Obviously, using this test is the most accurate way to calculate your BMR but that is to expensive.

All web based calorie calculators *estimate* your BMR based upon various research that has been done. These research studies have come up with various formulas that are used to estimate your calories. The Mifflin-St Jeor equation done in 1990, is based upon his research and is easy to use but only to get you to within about +/-10% accuracy on the caloric estimation which is accurate enough for most uses given the difficulty of counting the calories accurately. The reason for the +/-10% variation is twofold. First, because these equations use weight and not lean body mass in their calculations. The energy required to maintain muscle is higher than the energy required to maintain fat so both these equations will be off for either very lean or very fat people. To get around this problem there are two more sets of equations based upon the research by Katch-McArdle and Cunningham which are based upon Lean Body Mass (LBM) instead of weight. Everything has flaws and the Cunningham and Katch-McArdle equations do to. Their flaw is that they completley disregard the energy required to maintain the bodyfat so they are not accurate for untrained obese people. Whose equations should you use for best accuracy? If you are fairly muscular and lean (4-pack abs or better), we would recommend the Katch-McArdle formula. If you are just starting on your fitness journey and are not yet strong or lean then we recommend the Mifflin-St Jeor equation.

So back to the question, if all web calorie calculators out there use the same sets of equations, how can ApexMortals calculators claim to be the most accurate? Two reasons. First most web based calorie calculators out there are based upon the Harris-Benedict equations and Mifflin-St Jeor equations that use weight, not LBM (Lean Body Mass) for their calculations. Secondly, because of an innovative new procedure ApexMortals came up with to allow you to calibrate the calculator for your own, individual metabolism. After you have done the calibration, its very easy for you to approach the accuracy that you would get in a medical laboratory. The calibration procedure takes a month and we won't lie, it's a lot of work. For most people, just using the equations that get you within 10% are close enough and it's not worth the bother to calibrate. For serious bodybuilders though, having this accurate information is critical. Since serious bodybuilders are already methodically taking all the data required for this calibration, it's not much work for them at all and the gain in accuracy makes a huge difference.

Most people who “can't lose fat” are overestimating their weekly cardio time. Only strenuous cardio counts, things like jogging, biking up mountains, swimming, etc. Walking is great exercise but it does not count toward the hourly total nor does lifting weights – we assume you do these things. To count as strenuous cardio, it needs to be above 65% of your maximum heart rate for the entire exercise duration. This is especially important to monitor if you are using stationary cardio equipment where its easy to slack off.