Key takeaways
- BMR is your body’s baseline energy burn. It’s the number of calories you burn at rest just to stay alive, and it makes up the majority of your daily energy use.
- Muscle boosts your metabolism. The more muscle you’ve got, the higher your BMR, meaning you burn more calories even while sitting still.
- Understanding your BMR gives you control. Once you know your BMR and total daily energy expenditure (TDEE), you can tailor your diet and training to match your weight goals.
Tried counting calories and still not seeing the results you expected? Your basal metabolic rate (BMR) might be the missing piece.
Think of BMR as your body’s energy baseline — the calories you burn just by existing. Breathing, digesting, keeping your heart beating. Not exactly action-hero stuff, but it’s what keeps you alive.
And if you’re serious about shifting fat or building muscle, understanding your BMR is a game-changer. It’s like finally flicking on the lights in a room you’ve been stumbling around in.
What is basal metabolic rate?
Your basal metabolic rate (BMR) is the number of calories your body burns at rest — no movement, no exercise, just staying alive [1].
We’re talking:
- Heart pumping
- Lungs inflating
- Brain ticking over
- Skin regenerating
It’s not the same as your resting metabolic rate (RMR), which can be measured under looser conditions. BMR is calculated under strict criteria — fasted, fully rested, in a neutral temp room [2].
Why does this matter? Because once you know your BMR, you can calculate your total daily energy expenditure (TDEE), the full number of calories your body burns in a day, by adding things like exercise, food digestion, and even fidgeting to the equation [3].
Here’s what makes up TDEE:
- BMR (your body’s base calorie needs)
- Physical activity (from walking the dog to HIIT workouts)
- Thermic effect of food (yes, even digestion burns calories)
- Non-exercise activity thermogenesis (NEAT — think fidgeting, doing the dishes, pacing during phone calls)
Your BMR accounts for 60–75% of your total energy burn [4]. That’s why it’s so important. And the more muscle you have, the higher your BMR — muscle burns more calories than fat [5]. So strength training? Absolutely worth it.
How is BMR calculated?
Your BMR is based on four main things:
- Age
- Sex
- Height
- Weight
Basically, the bigger or more muscular you are, the more calories you’ll burn at rest.
There are two popular formulas to estimate BMR:
Harris-Benedict Equation
One of the older methods. Still decent, but tends to slightly overestimate for people with higher fat mass and lower muscle [7].
Mifflin-St Jeor Equation
The gold standard these days. Uses the same info as Harris-Benedict, but is more accurate for the average bloke [7]. Basically, the formula is:
BMR = 10 × weight (kg) + 6.25 × height (cm) – 5 × age (years) + 5
Once you've calculated your BMR, multiply it by an activity factor (anywhere from 1.2 for sedentary to 1.9 for very active) to estimate your TDEE, the number of calories your body burns in a day.
Want to make it easy? Just search for a free BMR calculator online. Make sure it uses the Mifflin-St Jeor formula and asks for your age, weight, height, and activity level.
What’s a healthy BMR?
There’s no one-size-fits-all number. Your BMR is personal — based on your build, lifestyle, and how active you are.
Generally:
- Younger blokes and those with more muscle = higher BMR
- As you age, your metabolism naturally slows down
Instead of chasing a perfect number, think of your BMR as a starting point. Once you’ve got it, you can work out your TDEE and figure out how much you should be eating depending on whether your goal is to cut, maintain, or bulk.
High BMR vs low BMR — what’s the deal?
- High BMR = you burn more energy just by existing. This is often the case if you’re muscular, taller, or genetically lucky.
- Low BMR = your body needs fewer calories to keep the lights on. It’s not bad, just means you’ll need to be a bit more strategic with diet and exercise.
Things like ageing, losing muscle, or underlying health conditions can lower your BMR [8]. If your calorie intake doesn’t match that shift, weight gain can creep in.
Bottom line: You can’t “fix” your BMR overnight, but you can work with it. Strength training, staying active, and dialling in your diet all help.
Can you change your BMR?
Technically, yes. But don’t expect miracles overnight.
Your BMR is mostly locked in by genetics, age, and body composition — but adding lean muscle mass can give it a boost. Muscle burns more calories than fat, even when you’re not doing anything [9].
So if your goal is to shift fat and stay lean? Prioritise resistance training, hit your protein targets, and keep active.
The bottom line
Knowing your BMR won’t solve everything — but it gives you a solid starting point.
Once you’ve figured it out, you can make smarter calls about how much to eat, how hard to train, and what kind of routine fits your goals.
If you’re keen to lose weight and build muscle but aren’t sure where to start, Pilot’s weight loss program can help.
It combines hands-on support from a team of health coaches — who can guide you through everything from optimising your diet for effective muscle building to figuring out the right strength training exercises — with science-backed weight loss solutions and access to a community of other men on a similar journey.
In short, you’ll have all the tools you need to get your muscle-building journey off to a stellar start.
No guesswork. No gimmicks. Just a better way to understand your body and take control of your results.
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