BMR & TDEE Calculator: Estimate Your Daily Calorie Burn

If you have ever wondered exactly how many calories your body burns in a day, you are already thinking about two of the most important numbers in nutrition: BMR (Basal Metabolic Rate) and TDEE (Total Daily Energy Expenditure). BMR is the energy your body uses just to stay alive — breathing, pumping blood, keeping your organs working — while you are completely at rest. TDEE builds on that baseline by adding the calories you burn through daily movement, exercise, and digestion. Together, they tell you the real number of calories you need each day to lose, maintain, or gain weight.

Our free BMR & TDEE Calculator does all of this math for you in seconds. You can try it right now at BMR & TDEE Calculator. It uses the well-regarded Mifflin-St Jeor equation, gives you five activity levels to choose from, applies six built-in goal presets, and even breaks your target calories into a protein/carb/fat macro split — all without sending a single piece of data to a server.

The reason these two numbers matter so much is simple: calorie balance drives weight change. Eat noticeably less than your TDEE and you lose weight; eat noticeably more and you gain. The tricky part is estimating that number accurately, which is exactly where a reliable calculator saves you from guesswork. Read on to learn how BMR and TDEE work, how to use the tool, and how to turn the results into a practical nutrition plan.

Why Use the BMR & TDEE Calculator?

• Data privacy — The calculator runs entirely in your browser. Nothing you enter (weight, height, age, gender) is ever transmitted to a server, stored, or tracked. Your numbers stay yours.
• Mifflin-St Jeor accuracy — This equation is the standard recommended by most dietitians and sports nutrition organizations, and it is more accurate than the older Harris-Benedict formulas for the general population.
• Five activity levels — Real lives vary. Whether you sit at a desk all day or train hard six days a week, there is a multiplier that matches your routine.
• Six goal presets — From extreme loss to muscle gain, the tool applies a sensible calorie adjustment automatically so you do not have to do the arithmetic.
• Built-in macro split — Knowing your calorie target is only half the battle. The calculator hands you a protein/carb/fat breakdown ready to plug into any tracking app.
• Metric and imperial units — Switch effortlessly between kilograms/centimeters and pounds/inches. No manual conversions required.

Key Features

• Every result updates instantly as you type, so you can experiment with different weights or activity levels in real time.
• Use the Copy button to grab your full results (BMR, TDEE, target calories, and macros) and paste them into a notes app or tracker.
• The Reset button clears everything in one click when you want to calculate for somebody else.

How to Use the Calculator

1. Enter your stats — Input your age, gender, weight, and height. Toggle the unit switch at the top if you prefer pounds and inches over kilograms and centimeters.
2. Pick your activity level — Choose the option that best matches an average week, not your best day. Honest selection here gives the most useful TDEE.
3. Select a goal — Pick from Extreme loss, Weight loss, Mild loss, Maintain, Mild gain, or Weight gain. The tool applies the right calorie adjustment automatically.
4. Read your results — You will see your BMR, your TDEE at the chosen activity level, your adjusted target calories for the goal, and a full macro split in grams.
5. Copy or reset — Hit Copy to save the breakdown, or Reset to start fresh with new inputs.

Understanding BMR and TDEE

BMR vs. RMR

BMR (Basal Metabolic Rate) and RMR (Resting Metabolic Rate) are often used interchangeably, but they are not identical. BMR is measured under strict clinical conditions — after a full night's sleep, in a thermally neutral room, fasting and completely at rest. RMR is measured under looser conditions and is usually slightly higher because the subject may have eaten or moved recently. For everyday nutrition planning, the difference is small enough that most calculators (this one included) use a predictive equation for BMR and treat it as your resting baseline.

The Mifflin-St Jeor Equation

This calculator uses the Mifflin-St Jeor equation, widely considered the most accurate predictive formula for healthy adults. It estimates BMR from weight, height, age, and gender:

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

The only difference between the two is the final constant (+5 for men, −161 for women), reflecting the different body-composition profiles between sexes.

How Activity Multipliers Work

BMR is just your resting baseline. To get your TDEE, you multiply BMR by an activity factor that reflects how much you move:

A Worked Example

Take a 30-year-old male, 80 kg, 178 cm, who trains moderately (3–5 days a week):

1. BMR = 10 × 80 + 6.25 × 178 − 5 × 30 + 5 = 800 + 1112.5 − 150 + 5 = 1767.5 kcal/day
2. TDEE at Moderate (1.55) = 1767.5 × 1.55 ≈ 2740 kcal/day
3. Weight-loss target (−500 kcal) = 2740 − 500 = 2240 kcal/day
4. Macro split at 2240 kcal:
   • Protein (30%): 672 kcal ÷ 4 = 168 g
   • Carbs (40%): 896 kcal ÷ 4 = 224 g
   • Fat (30%): 672 kcal ÷ 9 = 75 g

That is a complete, actionable starting plan — generated in seconds from four inputs.

Practical Use Cases

Weight Loss Calorie Deficit

The most common reason people use a TDEE calculator is fat loss. The classic rule of thumb is that a 500 kcal/day deficit yields roughly one pound (about 0.45 kg) of fat loss per week, because a pound of body fat stores approximately 3500 kcal. The calculator's Weight loss preset applies exactly this deficit. If you have a lot to lose and your TDEE is high enough, the Extreme loss (−1000 kcal) option is available, but it should be approached carefully and ideally with professional guidance. For most people, the safer Mild loss (−250 kcal) is a sustainable entry point that produces steady progress with fewer hunger pangs.

Lean Bulking / Muscle Gain

If your goal is to build muscle without piling on excess fat, a small surplus is your friend. The Mild gain (+250 kcal) preset gives you enough extra energy to recover and grow from hard training while minimizing fat gain. Pair the result with the macro split — making sure you hit the protein target of around 1.6–2.2 g per kg of body weight — and you have the nutritional backbone of a lean bulk. The 30% protein default in this tool comfortably lands most lifters in that range.

Cutting for Competition

Bodybuilders, fighters, and other weight-class athletes often need to cut aggressively while preserving muscle. Starting from an accurate TDEE lets you dial in a precise deficit — often cycling between Weight loss and Extreme loss presets as a show or weigh-in approaches. The macro readout helps you keep protein high (to protect lean mass) while trimming carbs and fat.

Maintenance and Recomposition

Not everyone wants to change the scale. If your goal is to recompose — slowly lose fat and build muscle at roughly the same body weight — choose Maintain (0 kcal adjustment) and focus on hitting your protein target while training hard. Knowing your exact maintenance calories removes the guesswork and keeps your weight stable while your body composition shifts over months.

Best Practices

• Be honest about activity level. People consistently overestimate how active they are. If you work a desk job and train three times a week, Light or Moderate is usually more accurate than Active.
• Re-check every few weeks. As your weight changes, so does your BMR. Recalculate after every 2–3 kg of change so your targets stay accurate.
• Track your food for a week before adjusting. Real data beats assumptions — log your intake honestly and compare it to the calculator's target.
• Prioritize protein. Whatever your goal, the 30% protein default supports muscle retention during deficits and muscle growth during surpluses.
• Use the result as a starting point, not gospel. Predictive equations have a margin of error. Adjust by 100–200 kcal based on real-world progress over two to three weeks.
• Protect your privacy. Because the tool is fully client-side, you can calculate for sensitive situations (medical diets, eating-disorder recovery, competition prep) without any data being stored.

Start Calculating Your Calories

You now have everything you need to turn a few simple inputs into a complete nutrition blueprint: BMR, TDEE, goal-adjusted calories, and a macro split. Head over to the BMR & TDEE Calculator, plug in your numbers, and take the guesswork out of your next training block — whether that is a cut, a lean bulk, a recomposition, or simply learning what maintenance looks like for you. It is free, private, and takes less than a minute.

Related Tools You Might Like

• BMI Calculator — Check your Body Mass Index and see where you fall on the standard ranges.
• Calorie Calculator — Another quick way to estimate daily calorie needs across different goals.
• Body Fat Calculator — Estimate your body fat percentage for a fuller picture of your composition.

Happy tracking!