“How many calories should I eat?”
That’s a question I hear a lot.
And my answer is…it depends.
These fundamental rules of dieting are based on the laws of energy balance.
They aren’t negotiable. There’s no way around them.
No matter how “clean” you eat, if you feed your body more energy than it burns, you will get fatter.
And, as a corollary, no matter how “dirty” your diet is, if you feed your body less energy than it burns, you will lose fat.
Don’t believe me?
Well, Professor Mark Haub lost 27 pounds on a diet of protein shakes, Twinkies, Doritos, Oreos, and Little Debbie snacks…
…and you could do exactly the same if you wanted to (not that you should though–nutrition does matter).
So, proper dieting starts with knowing how much energy you’re burning.
And that’s where accurately calculating your total daily energy expenditure (TDEE) comes in.
I’m going to start this article with the calculator in case you’re already familiar with what TDEE is and how it relates to dieting and so you can get back to it easily and quickly in the future.
If you don’t quite understand TDEE, how it’s calculated, and how to use it to create meal plans that actually work, though, then keep reading!
Oh and in case you’re wondering, this calculator uses the Katch-McArdle equation. If you don’t know what that is/means, read on. 🙂
Total daily energy expenditure is exactly what it sounds like:
The total amount of energy you expend every 24 hours.
It’s often expressed in calories, which is a measurement of energy. One calorie is the amount of energy it takes to heat one kilogram of water one degree Celsius (also called a kilocalorie).
For example, I’m 31 years old, 6’2 and 190 pounds, and I lift weights for about 4 hours and do high-intensity interval cardio for about 1.5 hours per week, and my TDEE is about 3,000 calories.
Use this workout and flexible dieting program to lose up to 10 pounds of fat and build muscle in just 30 days…without starving yourself or living in the gym.
Your TDEE is comprised of your basal metabolic rate (BMR) plus additional energy burned through physical activity and the food you eat.
Let’s review each of these points separately.
1. Your basal metabolic rate is the amount of energy your body burns at rest.
It’s the minimum amount of energy it costs to stay alive.
2. When you move your body, it costs energy.
No matter how large or small or long or short an activity is, it burns energy. Simple enough.
3. When you eat food, it costs energy to digest and absorb.
This is known as the thermic effect of food, or TEF.
So…when you sum the energy your body burns to stay alive (BMR) and the energy burned through physical activity and digesting and absorbing food…you arrive at your TDEE.
And if that sounds complicated, don’t worry. It’s not. You don’t have to dust off your college algebra or take an Excel tutorial.
Metabolic researchers have already done all the heavy lifting for us and boiled it down to simple arithmetic.
There are several equations for that but I recommend the Katch-McArdle variant, which looks like this:
(where LBM is the lean body mass in kg)
This matters because muscle is metabolically active whereas body fat isn’t.
That is, two people can weigh the same but if one has a lot more muscle, his basal metabolic rate will be quite different.
Instead of tracking every step you take and noting readouts from cardio machines (they’re inaccurate anyway), the Katch-McArdle equation includes multipliers that you can apply to your BMR based on your general activity level.
This will give you a good starting point for determining how many calories you should eat, and then you can adjust based on how your body actually responds.
Now, here are the standard Katch-McArdle multipliers:
1.2 = sedentary (little or no exercise)
1.375 = light activity (light exercise/sports 1 to 3 days per week)
1.55 = moderate activity (moderate exercise/sports 3 to 5 days per week)
1.725 = very active (hard exercise/sports 6 to 7 days per week)
1.9 = extra active (very hard exercise/sports 6 to 7 days per week and physical job)
There’s something you need to know about activity multipliers, though:
They will probably overestimate the actual amount of energy you’re burning.
I don’t have any research to directly back that statement up but I’ve worked with thousands of people and consistently found it to be the case. It’s also common knowledge among experienced bodybuilders.
Simply put, if you use the above multipliers, you’ll probably place yourself in too small of a calorie deficit when cutting (resulting in less-than-optimal fat loss) and too large of a surplus when bulking (resulting in more-than-optimal fat gain).
And that means generally diminished returns on your efforts over time.
This is why I recommend you just use lower activity multipliers when calculating your TDEE.
Here’s how I do it:
1.1 = sedentary (little or no exercise)
1.2 = light activity (light exercise/sports 1 to 3 days per week)
1.35 = moderate activity (moderate exercise/sports 3 to 5 days per week)
1.45 = very active (hard exercise/sports 6 to 7 days per week)
1.6 to 1.8 = extra active (very hard exercise/sports 6 to 7 days per week and physical job)
Those multipliers should give you a more accurate starting point, and they are what are built into the calculator below.
Then, as noted above, you adjust intake based on how your body actually responds.
As I noted earlier, the thing that most dictates whether you gain or lose weight is energy balance.
Energy balance is the relationship between the energy you feed your body and the energy it expends.
You see, the scientifically validated, “boring” reality is this:
If you’re shaking your head, thinking I’m drinking decades-old Kool-Aid, let me ask you a few questions.
Why has every single controlled weight loss study conducted in the last 100 years…including countless meta-analyses and systematic reviews…concluded that meaningful weight loss requires energy expenditure to exceed energy intake?
Why have bodybuilders dating back just as far…from Sandow to Reeves and all the way up the line…been using this knowledge to systematically and routinely reduce and increase body fat levels?
And why do new brands of “calorie denying” come and go every year, failing to gain acceptance in the weight loss literature?
The reality is a century of metabolic research has proven, beyond the shadow of a doubt, that energy balance, which operates according to the first law of thermodynamics, is the basic mechanism that regulates fat storage and reduction.
That doesn’t mean you have to count calories to lose weight…but it does mean you have to understand the relationship between calorie intake and expenditure and weight gain and loss.
When it comes to calculating your TDEE, keep it simple and remember it isn’t 100% accurate, nor is it supposed to be.
You’re looking for a starting point for your meal planning, not a definitive judgment on your energy expenditure.
You’ll probably find through actual experience that your body burns a bit more or less energy than formulas predict.
That’s just part of the game.
So, use this TDEE calculator to determine a baseline for your caloric intake, turn it into a well-designed meal plan, adjust as needed, and you’ll reach your goals.