How to Use the TDEE Calculator for Weight Loss, Maintenance & Muscle Gain
Select your gender, enter your age, weight, and height, then choose your activity level from the five options: Sedentary (desk job, minimal movement), Lightly Active (light exercise 1–3 days/week), Moderately Active (moderate exercise 3–5 days/week), Very Active (hard exercise 6–7 days/week), or Extremely Active (physical job plus daily exercise). The calculator instantly shows your BMR (Basal Metabolic Rate) — calories burned at rest — and your TDEE (Total Daily Energy Expenditure) — your total daily calorie burn including all activity.
Use your TDEE as the baseline for your calorie target. For weight loss, subtract 300–500 calories from your TDEE to create a moderate deficit. A 500-calorie daily deficit produces approximately 1 lb (0.45 kg) of fat loss per week — the most widely supported sustainable rate in clinical nutrition research. For maintenance, eat at your TDEE. For muscle gain (lean bulk), add 200–300 calories above your TDEE — enough to support muscle protein synthesis without excessive fat gain. Recalculate your TDEE whenever your weight changes by 10+ lbs or your activity level shifts significantly, since TDEE decreases as body weight decreases during a diet.
Why Use This Free TDEE Calculator?
- Uses the Mifflin-St Jeor equation — the most accurate BMR formula validated by modern research over the older Harris-Benedict formula
- Metric and imperial unit toggle so you can enter weight in kg or lbs, height in cm or feet/inches
- Shows both BMR and TDEE clearly so you understand what each number means and why they differ
- Displays five calorie goal presets color-coded by goal (aggressive cut, moderate cut, maintain, moderate bulk, aggressive bulk)
- Free with no sign-up required — get your TDEE in under 30 seconds
- Includes medical disclaimer — TDEE estimates require professional validation for clinical decisions
- 100% browser-based — your health data never leaves your device
Frequently Asked Questions
What is TDEE and why does it matter for weight loss?
TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in 24 hours, accounting for your resting metabolism, daily movement, exercise, and the energy cost of digesting food. It is the single most important number for any diet plan because it defines your energy balance. If you eat more calories than your TDEE, you gain weight; if you eat fewer, you lose weight. Without knowing your TDEE, any calorie target is a guess. Most nutrition apps and diet plans set arbitrary calorie targets (e.g., 1,200 or 2,000 cal) that may be too low or too high for your specific body and activity level. Calculating your actual TDEE gives you a personalized baseline to work from.
What is the difference between TDEE and BMR?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just to maintain vital functions like breathing, circulation, and cell repair. Think of BMR as the minimum calories required to survive if you stayed in bed all day. TDEE is BMR multiplied by an activity factor that accounts for all the additional energy you burn through daily movement, exercise, and non-exercise activity thermogenesis (NEAT). For most people, TDEE is 1.2–1.9× their BMR. You should always set your calorie target based on TDEE, not BMR — eating at your BMR level while being physically active creates an excessively large deficit that can cause muscle loss, fatigue, and metabolic adaptation.
How accurate is a TDEE calculator?
TDEE calculators based on the Mifflin-St Jeor equation are typically accurate within 10–15% of your actual expenditure for most people. Research comparing the Mifflin-St Jeor equation against indirect calorimetry (the gold standard measurement) found it accurate within ±200 calories for approximately 80% of subjects. However, individual variation is real — factors like muscle mass, gut microbiome composition, hormonal status, and medication use can all affect true metabolic rate. Use the calculator's estimate as a starting point, then track your actual calorie intake and body weight for 2–3 weeks. If your weight is stable at that intake level, the estimate was accurate. If you're losing or gaining weight unexpectedly, adjust by 100–200 calories and re-evaluate.
Source: PubMed — Comparison of predictive equations for resting metabolic rate
How do I use my TDEE for weight loss?
To lose weight using your TDEE: (1) Calculate your TDEE with this calculator using your current weight and honest activity level. (2) Subtract 300–500 calories per day to create a sustainable deficit. A 500-calorie deficit produces ~1 lb/week of fat loss; a 300-calorie deficit produces ~0.6 lb/week at a more comfortable pace. (3) Track your actual food intake using a calorie counting app (MyFitnessPal, Cronometer, Lose It!) and aim to hit your target consistently. (4) Recalculate your TDEE every 4–6 weeks or after every 10 lbs lost, since TDEE decreases as body weight decreases. Avoid deficits larger than 1,000 calories/day as these dramatically increase muscle loss risk and are difficult to sustain. For most people, a 400–500 calorie deficit combined with protein intake of 0.7–1g per lb of body weight is the most effective approach for fat loss while preserving muscle.
How many calories should I eat to lose 1 pound per week?
A 3,500-calorie total deficit produces approximately 1 pound of fat loss. To lose 1 pound per week, you need a daily deficit of 500 calories (500 × 7 = 3,500). Subtract 500 from your TDEE to get your weight loss calorie target. For 0.5 pounds per week (a more sustainable, muscle-preserving pace), subtract 250 calories from your TDEE instead. Note that the 3,500 calories = 1 pound rule is an approximation — actual fat loss also depends on water retention, glycogen depletion, and hormonal factors, so week-to-week scale fluctuations are normal even in a consistent deficit.
Source: NIH — Modeling the Dynamics of Human Body Weight Change
What activity level should I choose in the TDEE calculator?
Choose the activity level that best represents a typical week — not your best week. Sedentary: desk job, no structured exercise or less than 1 workout/week. Lightly Active: 1–3 light-to-moderate workouts per week (e.g., 30-minute gym sessions, daily short walks). Moderately Active: 3–5 genuine workouts per week at moderate-to-hard effort. Very Active: 6–7 hard training sessions per week or a physically demanding job. Extremely Active: both a physical job and daily hard training. Most people with desk jobs who go to the gym 3–4 times per week fall into Lightly Active or Moderately Active — not Very Active. When uncertain, choose one level lower and adjust upward after 2–3 weeks of tracking if your weight is dropping faster than expected.
Should I eat back calories burned during exercise?
If your TDEE calculation already accounts for your exercise level (which it does when you select the correct activity multiplier), then no — exercise calories are already baked into your TDEE. Only eat back exercise calories if you calculated TDEE at Sedentary level and then did additional exercise beyond your baseline. Be cautious with calorie burn estimates from fitness trackers and gym equipment, as research consistently shows they overestimate calorie expenditure by 20–40%. If you use a fitness app that adds exercise calories to your daily budget, make sure you're not double-counting by also using a high activity multiplier in your TDEE.
Source: PubMed — Accuracy of Wearable Trackers for Measuring Energy Expenditure
What is the Mifflin-St Jeor equation used by this calculator?
The Mifflin-St Jeor equation (1990) calculates Basal Metabolic Rate (BMR) from weight, height, age, and sex. For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. For women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161. TDEE is then calculated by multiplying BMR by an activity factor (1.2 for sedentary to 1.9 for extremely active). A 2005 meta-analysis in the Journal of the American Dietetic Association found the Mifflin-St Jeor equation to be the most accurate of four commonly used BMR formulas, predicting BMR within 10% of measured values for the highest percentage of subjects compared to Harris-Benedict (1919), Owen (1986), and WHO/FAO/UNU formulas.
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