TDEE Calculator — How Many Calories Do You Burn a Day?

What TDEE Actually Means

TDEE stands for Total Daily Energy Expenditure, which is a mouthful for a simple idea: it’s every single calorie your body burns in 24 hours. Not just the gym session. Everything. Breathing, digesting lunch, fidgeting at your desk, walking to the kitchen, sleeping — all of it adds up, and the total is your TDEE.

People tend to think calories only burn during exercise. Not even close. For most of us, the workout is the smallest slice of the pie. The vast majority of what you burn happens whether you train or not, just keeping you alive and moving through an ordinary day.

Here’s why this one number runs the whole show. Eat fewer calories than your TDEE and your body dips into its reserves — you lose fat. Eat more and the surplus gets stored — you gain weight, fat or muscle depending on how you train. Eat right around it and you hold steady. That’s the entire game. Every goal you’ve ever had with your body comes back to your number and which side of it you land on.

The Four Pieces of Your Daily Burn

Your TDEE isn’t one thing — it’s four things stacked together. Knowing them helps the whole picture click.

Your BMR (the big one). Basal Metabolic Rate is what you’d burn lying in bed all day doing absolutely nothing. Keeping your heart pumping, your brain firing, your organs running — that baseline alone eats up most of your calories. For most people it’s 60 to 70% of the total.

Moving about. Every step, every gym session, every time you carry the shopping in. This is the bit you can crank up or wind down, which is why active people burn so much more.

Digesting your food. Your body actually spends energy breaking down what you eat — it’s called the thermic effect of food. Protein is the hungriest to digest, which is part of why high-protein diets help with fat loss.

Fidgeting. Officially this is “NEAT,” but really it’s all the unconscious movement — tapping your foot, pacing on the phone, gesturing when you talk. Sounds trivial. It isn’t. Between two people it can differ by hundreds of calories a day.

How the Calculator Works Out Your Number

The tool above runs the Mifflin-St Jeor equation, and there’s a reason it picked that one. Out of all the formulas floating around, this is the one researchers keep finding to be the most accurate for the general population — more reliable than the older Harris-Benedict, and unlike Katch-McArdle, it doesn’t need you to know your body fat percentage first.

It runs in two steps. First it works out your BMR from your age, sex, height, and weight:

• Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
• Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Then it multiplies that BMR by an activity factor — a number that scales your resting burn up to match how much you actually move:

BMR times activity factor equals your TDEE. Job done.

The mistake almost everyone makes

I have to flag this because it trips up nearly everyone: don’t overestimate your activity level. It’s the single most common reason people’s numbers come out too high. That gym-goer who trains hard four times a week but sits at a desk the rest of the time? They’re “moderately active,” not “very active.” Be honest, even a little harsh, with that dropdown. Most people should pick one level lower than their ego wants to.

What to Do With Your Number

Once you’ve got your TDEE, the calculator hands you a few targets. Here’s how to actually use them.

To lose fat

Eat below your TDEE. A deficit of around 500 calories a day is the classic starting point — it works out to roughly a pound of fat a week, which is steady and sustainable. You can go a touch bigger if you’ve got more to lose, but resist the urge to slash it dramatically. Brutal deficits burn muscle, tank your energy, and almost always end in a binge.

To maintain

Eat right at your TDEE. Simple as that. This is where you land once you’ve reached a weight you’re happy with, and honestly, knowing your maintenance number is freeing — you stop fearing food and just eat to hold your ground.

To build muscle

Eat above your TDEE — but only a little. A surplus of 250 to 300 calories is plenty to fuel muscle growth without piling on needless fat. The old “dirty bulk” approach of eating everything in sight just leaves you with more fat to cut later. Lean and patient wins.

Whatever your goal, once you know your calories the next question is how to split them between protein, carbs, and fat. That’s exactly what our Macros Calculator sorts out for you.

How Accurate Is Your TDEE, Really?

Time for some honesty. Your TDEE is an excellent estimate — but it is an estimate. Validated formulas like Mifflin-St Jeor land within about 10% of your true burn for most people. Good enough to start with confidence, not so perfect that you should treat it as gospel.

Why the wiggle room? Bodies vary. Two people identical on paper can have genuinely different metabolisms thanks to genetics, hormones, how much muscle they carry, even how much they unconsciously fidget. The formula can’t see any of that.

So here’s the smart way to use your number. Treat it as your starting line, not the finish. Eat at your calculated target for two or three weeks and watch what the scale does. Losing faster than you wanted? Nudge calories up a little. Not moving at all? Trim them down by a hundred or two. Your real-world results are the ultimate calculator — the formula just gets you in the right ballpark fast.

TDEE, BMR, BMI — Sorting Out the Acronyms

These three get muddled constantly, so let’s pin them down:

• BMR is what you burn at complete rest. The baseline.
• TDEE is BMR plus everything you do. Your real daily burn.
• BMI is something else entirely — just a height-to-weight ratio, nothing to do with calories.

You’ll use them for different jobs. TDEE sets your calorie target. BMR shows you the floor you shouldn’t eat below. And BMI gives you a rough health screen — check yours on our BMI Calculator if you’re curious. Three tools, three purposes.

One more thing worth clearing up: don’t “eat back” your exercise calories on top of your TDEE. Your activity multiplier already baked your training into the number. Adding workout calories again is double-counting, and it’s a quiet way to wonder why the fat won’t budge.

Frequently Asked Questions