How many calories do you actually need?
Not for a diet, not for a specific goal, just to fuel your own body? Your number comes from two things multiplied together: your basal metabolic rate (BMR) and your physical activity level (PAL). That gives you your maintenance calories – the number that keeps your weight stable, no goal attached.
Working in the fitness and health industry for over 13 years, studying nutrition at MNU, and practicing as an evidence-based coach, this is the exact starting point I teach every client before anything else.
BMR – what it is and how to calculate it
Basal metabolic rate (BMR) is the energy your body uses at total rest just to stay alive – organ function, cell repair, breathing. It has nothing to do with movement. You can imagine that this is the energy your body needs even if you were in a coma or just sleeping for a whole day.
There are several equations to calculate it. I use two or three and take the mean of those rather than relying on just one. My top choices, based on the current evidence, are Mifflin-St Jeor, Cunningham (if you know your body fat percentage), and the revised Harris-Benedict equation.
Let me show you this in practice:
Mifflin-St Jeor:
For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5
For women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161
Harris-Benedict (revised):
For men: BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) − (5.677 × age in years)
For women: BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) − (4.330 × age in years)
Cunningham:
General formula: BMR = 500 + (22 × lean body mass in kg)
Based on my current age (34), weight (52 kg), and height (164 cm), my BMR is ~1,252 kcal. I used only two equations because I don’t know my body fat percentage. If you are likewise not an athlete and focus on general health, you are also good without it.
One important note: BMR is an estimate, not a measured fact. Two people with identical numbers can have real differences in their actual metabolic rate. That’s fine – you don’t need to over-optimize this; you need a starting point. If you want to keep it simple, Mifflin-St Jeor alone is enough. If you want more precision, average a couple of the equations above.
PAL – what “physical activity level” actually means and how to estimate yours
Your physical activity level (PAL) is a multiplier representing how much you move in daily life – outside of structured exercise. It comes from your typical day: your job, household chores, how much you’re on your feet versus sitting, and your weekend, morning, and evening routines. Training or workouts aren’t part of this – that’s calculated separately.
Here’s mine as an example: I work from home, mostly sitting, with light household chores, shopping twice a week, and a more active weekend – hiking, getting out of the house. On a normal day, I work 10–12 hours, spend 2–3 hours cooking and on chores, and get maybe an hour of walking. That puts me at sedentary to lightly active – a PAL of around 1.3.
PAL tiers that you can use for your estimates:
| Level | PAL range | What it looks like |
| Sedentary | 1.2–1.3 | Desk job, minimal movement, little walking outside of work |
| Lightly active | 1.3–1.5 | Some walking or standing through the day, light chores, occasional errands |
| Moderately active | 1.5–1.7 | On your feet for much of the day – teaching, nursing, retail, active parenting |
| Very active | 1.7–1.9+ | Physically demanding job plus a highly active lifestyle outside it – manual labour, hospitality, farming |
As you can see, the PAL number doesn’t reflect intense workouts. I’m a personal trainer, but with mainly online work, so my physical activity level is very low – that doesn’t define me; it just gives me feedback on the amount of energy my body consumes.
It’s important to accept this, as you can misjudge this number and, as a result, overestimate the amount of calories you need.
If you have regular exercise, you add that amount of energy separately.
Estimating this level is not easy. It takes some practice and different scenarios, but for a rough estimate you can easily use the table above and set your number. Just make sure you really reflect the truth and don’t over- or underestimate.
TDEE and what “maintenance calories” really means
Total daily energy expenditure (TDEE) is your BMR multiplied by your PAL. Using my numbers above: 1,252 × 1.3 ≈ 1,628 kcal. That’s the energy my body needs to sustain daily life and basic functions – no exercise counted, no goal counted.
TDEE is the maintenance calories in this scenario: the number that keeps your weight stable. No weight loss, no muscle gain.
According to the Cleveland Clinic, BMR typically accounts for 60–70% of total daily energy expenditure – which is why getting that number right matters more than most people assume, and why it’s worth doing properly rather than guessing.
For general health, BMR multiplied by PAL is the amount of energy we have to focus on. And most of the time in my work, this is the amount we use – and when a client wants to change the appearance of their body but doesn’t really need significant fat loss, we pay attention to higher protein intake, adequate sleep, hydration, and enough fiber and vegetables. Yes, the boring things really work.
How to add extra calories if you are also working out every week?
Exercise adds a small amount on top of your maintenance, and it can be calculated more precisely using the exercise MET amount, intensity, duration, and weekly frequency. It’s not impossible to calculate, but it does add some complexity. I’ll cover this in its own article, as it takes a hot minute to explain it well.
As a rough estimate: a low-to-moderate intensity workout at the gym under an hour adds roughly 50–100 extra calories a day. But this is super dependent on your age, sex, intensity, temperature, health, level of fitness, the type of workout, the duration, and the list could go on.
For most people doing general training, that’s a small number relative to total daily energy – one more reason workouts alone rarely move the needle on weight loss the way people expect.
What to do with your number – where macronutrients come in
Once you have your maintenance calories, the next step is macronutrients – protein, carbohydrates, and fats. For general health, you don’t need a perfect number here, just a working range.
Protein works best somewhere between 1.2–1.6 g per kg for general health, a bit higher for performance training, and higher again for bodybuilding-specific goals; most people land comfortably in that first range.
Carbohydrates generally fall between 1–3 g per kg, depending on activity and individual variation; two people with similar lifestyles can need different amounts, and that’s normal.
Fat doesn’t have as clear a range, but 20–40% of total calories works well for most people; very low (below 15%) fat intakes shouldn’t be a long-term habit, since fat plays a real role in hormones, immune function, and overall health.
This is a preview, not the full picture – a proper macro breakdown deserves its own article, which I’ll cover separately.
The takeaway
Once you know your BMR, estimate your PAL, and multiply the two, you have the calories your body actually needs – a far better starting point than following a random 1,200-calorie recommendation, which is too low for most healthy adults.
From there, you can calculate a brief amounts for the macronutrients so you have a good understanding what your body really need.
As this article is meant to give a good understanding of calorie calculations, we didn’t go into the details of those, but I will share more on that in the upcoming articles.
I work with women and men navigating pain, movement, and nutrition, online and in person. Book a free call and we’ll set your numbers up together, or try my calculator for an instant BMR and workout-adjusted estimate.
FAQ
Who is this article for?
Anyone who wants to understand how their calorie needs actually work – no specific goal required. Whether you’re maintaining, planning a future change, or just tired of guessing, this gives you the fundamentals underneath any goal.
How is this different from an online calculator?
A calculator gives you a number with no context. This explains why that number is what it is, so when your real-world results don’t match it, you know how to adjust rather than assuming the tool is broken.
How long before I know if my number is right?
Around two weeks of consistent tracking against real-world weight stability. If your weight holds steady at your calculated maintenance number, it’s accurate enough to work from.
Do I need to recalculate this as things change?
Yes. A meaningful change in weight, activity level, or daily routine is worth recalculating for – your BMR and PAL aren’t fixed for life.
RESEARCH & references
Mifflin MD, St Jeor ST, et al. (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition.
Original paper establishing the Mifflin-St Jeor equation.
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Cleveland Clinic (2024). BMR (Basal Metabolic Rate): What It Is & How To Calculate It.
Source for the 60–70% BMR-to-TDEE figure used in the maintenance calories section.
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Phillips SM, Chevalier S, Leidy HJ. (2016). Protein “requirements” beyond the RDA: implications for optimizing health. Applied Physiology, Nutrition, and Metabolism.
Source for the 1.2–1.6g/kg general-health protein range.
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Phillips SM, Van Loon LJC. (2011). Dietary protein for athletes: From requirements to optimum adaptation. Journal of Sports Sciences.
Source for the higher performance and bodybuilding protein ranges.
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