What Is a TDEE Calculator?

A TDEE calculator (Total Daily Energy Expenditure calculator) estimates the total calories your body burns in a day — at rest and through every activity in your life. Most people confuse TDEE with BMR (Basal Metabolic Rate): BMR is what you burn lying completely still, while TDEE is what you actually burn living your real life — working, exercising, cooking, commuting. The gap between these two numbers is why so many people undereat and still don't lose weight: they're calculating a deficit against BMR when they should be calculating against TDEE.

Enter your age, sex, height, weight, and activity level, and this calculator returns your maintenance calories — the number to eat to hold your weight steady — along with adjusted targets for fat loss and muscle gain.

How to Use the TDEE Calculator

1. Enter your personal stats: Input your age, biological sex, height, and current weight. These feed into the Mifflin-St Jeor equation, validated by the Academy of Nutrition and Dietetics as the most accurate non-lab method for estimating resting metabolic rate.
2. Select your activity level honestly: Choose the level that reflects your average week — not your best week. Most desk workers with occasional gym visits are "lightly active," not "moderately active." Overestimating here is the single most common source of calorie miscalculation.
3. Choose your goal: Select maintain, lose weight, or gain muscle. The calculator will show your TDEE maintenance number and the adjusted targets for each goal.
4. Use your maintenance number as your baseline: Eat at TDEE and your weight stays stable. Subtract 500 kcal per day for ~1 lb/week fat loss. Add 250–500 kcal for a lean bulk.

BMR vs. TDEE: What's the Difference?

• BMR (Basal Metabolic Rate): The calories your body burns at complete rest — if you stayed in bed all day and didn't move a muscle. For most adults, BMR accounts for 60–70% of total daily calorie burn.
• TDEE: Your BMR multiplied by an activity factor that accounts for everything you do — walking, workouts, standing, even digesting food. Most people's TDEE is 1.2 to 1.9× their BMR depending on lifestyle. This is the number that actually determines whether you gain, lose, or maintain weight.

Who Is This For?

• People starting a calorie-counting diet who need their actual maintenance number before they can set a meaningful deficit — guessing at 1,200 kcal when your TDEE is 2,100 means you may be in a much larger deficit than intended, or not in one at all.
• Gym-goers who've hit a plateau and suspect they've been eating at the wrong level — often they're eating at BMR rather than TDEE, leaving a phantom surplus they can't account for.
• People recovering from undereating who need to know what normal calorie intake actually looks like for their size and activity level before carefully reverse dieting back to maintenance.

Key Benefits

• 100% private: Your stats are processed entirely in your browser and never sent to any server or stored anywhere.
• Free, no account needed: Use it as many times as you want — recalculate monthly as your weight and activity change.
• No subscription, no paywall: Full results every time, nothing locked behind a sign-up.
• Maintenance, deficit, and surplus in one calculation: One run gives you all three numbers so you can make an informed decision based on your goal rather than running the math separately.

Common Use Cases

Starting a cut after years of guessing: You've been eating 1,600 kcal thinking it's a deficit, but your TDEE is actually 1,580. Running your real stats through the calculator often reveals exactly why the scale isn't moving.

Breaking a fat loss plateau: After weeks of no scale movement, recalculate TDEE with your current (lower) weight. As you lose mass, your maintenance drops — what was a 500-calorie deficit is now 200, which explains the stall.

Reverse dieting after a long cut: If you've been in a deficit for months and want to increase calories without fat gain, your recalculated TDEE is the target to work back toward gradually over several weeks.

Frequently Asked Questions