Calculate a guideline daily calorific intake that will allow you to
lose fat fast without losing muscle!



  • Sedentary: You're on your butt most of the time.
  • Light: Significant calorie burning 1-3 times per week.
  • Moderate: Significant calorie burning 3-5 times per week.
  • Heavy: Significant calorie burning 6-7 times per week.
  • Extreme: Significant calorie burning many times per day.
  • Total Daily Energy Expenditure: 0 cals
  • Week 1, eat at least 0 cals/day
  • Week 2, eat at least 0 cals/day
  • Week 3, eat at least 0 cals/day
  • Week 4, eat at least 0 cals/day

Who is this intended for?

deflab.me is for all people (male or female) of a normal weight range looking to lose weight fast while preserving hard-won muscle. It is not intended for very overweight people, and should be used as a guide only. Every person is different, so one formula won't be perfect for everyone.

So how does this all work?

This tool uses a combination of the Katch-McArdle BMR formula, and research by SS Alpert and J Theor Biol. For a detailed explanation of the logic behind this, see the following thread on reddit.com. It's scientific, honest!

Total Daily Energy Expenditure?

Your Total Daily Energy Expenditure is the number of calories you need to consume to maintain your current body weight taking into account your activity level.

These deficits seem a little steep!

If you haven't done this before, they will do. deflab.me is designed around a formula to give the maximum deficit you can theoretically get away with when on a "cut". Remember, while cutting you'll be living off both your body fat and the calories you consume in food. So adjust your macronutrient ratios accordingly!

Get yourself featured here!

We're currently looking for success stories to display here. If you've found deflab.me useful then send us an email at admin@deflab.me with a name and some pictures and we'll show off your progress on-site!