TDEE Calculator Online — Free TDEE Calculator Tool
CodexFuse Team · 2026-11-06T13:55:51.426Z · 8 min read min read
Calculate your TDEE in seconds with our free TDEE calculator. Get daily calorie targets for weight loss, maintenance or muscle gain.
A TDEE calculator estimates how many calories your body burns in a typical day, from breathing and digestion to walking, working and training. Enter your age, weight, height, sex and activity level, and it returns a single daily calorie number you can build a diet around. The free tool on CodexFuse does exactly that in seconds, with no sign-up and no download.
Most diet plans fail for a simple reason: the calorie target was a guess. It replaces that guess with a number grounded in your body and your actual day, so weight loss, maintenance or muscle gain starts from evidence instead of hope.
What is a TDEE calculator?
A TDEE calculator estimates your Total Daily Energy Expenditure, the total calories your body uses in 24 hours. It combines your basal metabolic rate, the energy needed to keep you alive at rest, with the calories burned through daily movement and exercise, and returns one daily total. That total is the starting point for every calorie goal, whether you want to lose fat, hold your weight or build muscle.
Your TDEE has four parts: basal metabolic rate (roughly 60 to 70 percent), the energy used to digest food (about 10 percent), exercise, and non-exercise activity such as walking, standing and carrying groceries.
How does a TDEE calculator work?
The calculator first estimates your basal metabolic rate using the Mifflin-St Jeor equation, the formula most dietitians consider the most accurate for the general population. It then multiplies that figure by an activity factor that reflects how much you move, producing your total daily energy expenditure in calories.
For women, BMR equals 10 times weight in kilograms, plus 6.25 times height in centimetres, minus 5 times age, minus 161. For men, the same calculation ends with plus 5. The result is the calories you would burn lying still all day.
The activity multiplier then scales that number to real life:
| Activity level | Multiplier | What it means |
|---|---|---|
| Sedentary | 1.2 | Desk job, little or no exercise |
| Lightly active | 1.375 | Light exercise 1 to 3 days a week |
| Moderately active | 1.55 | Moderate exercise 3 to 5 days a week |
| Very active | 1.725 | Hard exercise 6 to 7 days a week |
| Extremely active | 1.9 | Physical job plus daily hard training |
If you are between two activity levels, choose the lower one. A slightly underestimated TDEE is safer than an overestimated one, because you can always add calories back after two weeks of tracking. It is far harder to undo weeks of overeating caused by an inflated target.
How to use the free TDEE calculator
Using the free tool takes less than a minute, and it follows three simple steps. First, enter your stats: age, weight, height and sex. Second, pick the activity level that best describes your typical week. Third, hit calculate and read your TDEE, along with the calorie goals for weight loss, maintenance and gain.
If your weight is in pounds, convert it first with the pounds to kg converter, and convert height to centimetres too. A small input error becomes a large calorie error later.
A worked example: Sara's numbers
Sara is a fictional 32-year-old marketing manager. She weighs 68 kg, stands 165 cm tall, works at a desk, and trains three times a week. She wants to lose fat without starving herself.
Her BMR works out to around 1,390 calories a day. Three gym sessions plus a desk job puts her at moderately active, a multiplier of 1.55, so her TDEE comes to about 2,155 calories a day.
For maintenance she eats around 2,155 calories. For fat loss she subtracts 500, giving a target of about 1,655 calories a day, which typically produces a loss of around half a kilo per week. For muscle gain she adds roughly 250, landing near 2,405 calories. One calculation, three clear targets.
Pair the result with a training plan. Once you know your calorie target, the AI workout plan generator turns your fitness goal into a weekly schedule you can actually follow, so the calories and the training point in the same direction.
What calorie target should you aim for?
| Goal | Adjustment to TDEE | Sara's target |
|---|---|---|
| Lose fat steadily | Minus 300 to 500 calories | 1,655 to 1,855 per day |
| Maintain weight | No change | About 2,155 per day |
| Build muscle | Plus 250 to 300 calories | About 2,405 per day |
A deficit larger than 500 calories a day is rarely a good idea. It makes hunger harder to manage, increases muscle loss, and is difficult to sustain for more than a few weeks.
Never eat below your BMR for long. Sara's BMR is about 1,390 calories, so a target of 1,655 leaves a safe margin. If your calculated deficit pushes you below your BMR, shrink the deficit instead. Very low calorie intakes without medical supervision can cause fatigue, hormonal disruption and muscle loss.
Why most TDEE results are wrong
Any calculator is only as good as the numbers you feed it. These four mistakes distort the result more than any flaw in the formula itself.
- Overstated activity: most people pick one level too high. A desk job with three gym sessions is moderately active, not very active. Be honest about the other 23 hours of your day.
- Out-of-date weight: entering the weight you were six months ago, or the one you wish you were, shifts the whole result. Weigh yourself the morning you calculate, before eating.
- Ignoring body composition: the standard formula uses total weight, so two people at 90 kg get the same BMR even if one is mostly muscle and the other mostly fat. Very muscular people may find the estimate slightly low.
- Treating the number as permanent: your TDEE changes as your weight changes. Lose 5 kg and your TDEE drops. Recalculate every time your weight moves by 3 to 5 kg, or every four to six weeks.
Stop eating to a number you made up. Run your real stats through the free tool, get a daily target built on your body and your week, and start eating with a plan. If you coach clients or run a fitness business, CodexFuse hosts your website, business email and backups on one fully managed platform, on credits, with no subscriptions to juggle.
Get Started with CodexFuseWhat the calculator cannot tell you
The tool gives you a number, not a diagnosis. It cannot measure your body fat percentage, detect a thyroid issue, or account for medication that affects metabolism. If you have a medical condition, are pregnant, or have a history of disordered eating, talk to a doctor or registered dietitian before setting a calorie target.
It also cannot judge food quality. Two diets at 1,655 calories can feel completely different: one built on protein, fibre and whole foods keeps you full, while one built on sugary snacks leaves you hungry by mid-afternoon.
Finally, remember that every TDEE figure is an estimate, typically within about 10 percent of your true expenditure. Track your weight for two weeks, then adjust: losing faster than planned means you can eat a little more, losing nothing means you trim 100 to 200 calories and check again.
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Frequently Asked Questions
Is the TDEE calculator free?
Yes. It is completely free with unlimited use, and you do not need to create an account or install anything. Enter your stats, pick your activity level and get your result instantly.
How accurate is it?
For most people it lands within about 10 percent of their true daily expenditure. That is accurate enough for a starting target. Track your weight for two weeks and adjust by 100 to 200 calories based on what actually happens.
What is the difference between BMR and TDEE?
BMR is the calories your body burns at complete rest, just to keep you alive. TDEE adds everything else: walking, working, digesting food and exercising.
How often should I recalculate my TDEE?
Recalculate whenever your weight changes by 3 to 5 kg, when your activity level changes, or at least every four to six weeks. As you lose weight your body needs fewer calories, so an old target can quietly become too high.
Should I eat back the calories I burn exercising?
Usually no. Your TDEE already includes exercise through the activity multiplier, so eating back the calories your watch reports would double count them. Only add calories back after an unusually long session, such as a multi-hour hike.
Can I use it for muscle gain?
Yes. Add roughly 250 to 300 calories above your TDEE, eat around 1.6 to 2.2 grams of protein per kilogram of bodyweight, and train with progressive overload. A small surplus builds muscle with minimal fat gain.
Start with your number, then stick to it
You now know what TDEE is, how the calculation works, and what Sara's numbers look like in practice. The only step left is running your own. Open the free TDEE calculator, enter your stats, pick your honest activity level, and write down your three targets. Then follow the number for two weeks before changing anything. If you run a fitness studio or coach clients online, move your website, business email and backups to CodexFuse today: one fully managed platform on pay-as-you-go credits, no subscriptions, no server babysitting.
