What Is TDEE?

Total Daily Energy Expenditure (TDEE) is an estimate of the calories your body uses across a full 24-hour day. It combines three main components described in the National Academies energy intake framework:

  • Resting energy (BMR/RMR) — calories to keep your heart, brain, and organs running at rest. Usually 60–75% of TDEE for sedentary adults.
  • Thermic effect of food (TEF) — energy used to digest, absorb, and store food. Roughly 8–15% of intake depending on macronutrient mix.
  • Physical activity (PAEE + NEAT) — structured exercise plus everyday movement like walking, standing, and fidgeting. This is the most variable component.

A TDEE calculator is useful because most people do not need a lab measurement to start making better nutrition decisions. The result is still an approximation — sleep, stress, daily routine, and normal day-to-day variation all move your real-world needs.

How This TDEE Calculator Works

Five steps — all running locally in your browser, nothing sent to a server.

1

Inputs

Age, gender, height, weight

2

BMR

Formula estimate at rest

3

Activity

Lifestyle multiplier

4

TDEE

Maintenance calories

5

Goal

Deficit, surplus, or macros

Worked example: 30-year-old woman

170 cm, 65 kg, moderately active, Mifflin-St Jeor, maintain goal.

  1. BMR ≈ (10 × 65) + (6.25 × 170) − (5 × 30) − 161 ≈ 1,402 kcal
  2. Activity factor 1.55 (moderately active)
  3. TDEE ≈ 1,402 × 1.55 ≈ 2,173 kcal/day maintenance
  4. Maintain goal → goal calories ≈ 2,173 kcal
  5. Macros split from goal calories and body weight

Result: Estimated maintenance ~2,170 kcal/day (rounded). Track for 2–3 weeks to verify.

BMR Formula Comparison

All three formulas estimate resting energy only. TDEE adds your activity multiplier on top.

Choose based on available inputs — not marketing claims.

Formula

Mifflin-St Jeor

Inputs needed

Age, sex, height, weight

Strengths

Default for most adults; well-validated in comparative research

Limitations

Does not use body composition directly

Formula

Revised Harris-Benedict

Inputs needed

Age, sex, height, weight

Strengths

Useful cross-check; long track record

Limitations

May overestimate vs measured RMR by ~50–80 kcal on average

Formula

Katch-McArdle

Inputs needed

Weight + body fat %

Strengths

Uses lean body mass; no age/sex in formula

Limitations

Only as good as your body fat estimate

Mifflin-St Jeor (default)

Male:
BMR = (10 × kg) + (6.25 × cm)
    − (5 × age) + 5

Female:
BMR = (10 × kg) + (6.25 × cm)
    − (5 × age) − 161
kg
Body weight in kilograms
cm
Height in centimeters
age
Age in years

TDEE = BMR × activity factor (1.2–1.9)

Activity Levels Decoded

Activity multipliers are broad shortcuts covering your job, steps, chores, and training. If you are between two levels, choose the lower one first.

Level

Sedentary

Factor

1.2

Practical cue

Desk job, little purposeful exercise

Step proxy

< 5,000/day

Level

Lightly Active

Factor

1.375

Practical cue

Light exercise or walking 1–3 days/week

Step proxy

5,000–7,500/day

Level

Moderately Active

Factor

1.55

Practical cue

Moderate training 3–5 days/week + normal movement

Step proxy

7,500–10,000/day

Level

Very Active

Factor

1.725

Practical cue

Hard training most days or active job

Step proxy

10,000–12,500/day

Level

Extra Active

Factor

1.9

Practical cue

Physical job plus high training load

Step proxy

12,500+/day

How Accurate Is This Estimate?

TDEE estimate error comes from two stacked layers — and the second is usually bigger in practice.

Layer 1: BMR formula error

Mifflin-St Jeor predicts resting metabolic rate within ~10% for roughly 82% of non-obese adults and ~70% of obese adults (Frankenfield et al., 2005). That is ±150–200 kcal for many people.

Layer 2: Activity multiplier error

Picking one activity bucket too high adds ~200–400 kcal/day. Most people remember gym time but underestimate desk hours. Take our Activity Level Quiz if unsure.

How to Interpret Your Results

What your calculator output means in plain language.

Your goal

Maintain

What the number means

Goal calories ≈ TDEE. Weight should stay relatively stable over weeks if intake matches.

Suggested next step

Track 2–3 weeks. Adjust ±100–200 kcal if trend drifts.

Your goal

Fat loss (deficit)

What the number means

Goal calories below maintenance. A 500 kcal/day deficit roughly maps to ~1 lb/week for many people — but real results vary.

Suggested next step

Use the Deficit Calculator to compare pace options. Prioritize protein.

Your goal

Muscle gain (surplus)

What the number means

Goal calories above maintenance. Small surpluses (+5–10%) are easier to control than large ones.

Suggested next step

Set macros with higher protein. Track scale and strength trends.

3-Week Calibration Protocol

Formulas give you a starting point. Your scale trend over 2–3 weeks is the best feedback loop for finding your real maintenance calories.

  1. Week 1: Eat at your estimated maintenance (or goal calories) as consistently as practical. Weigh yourself daily at the same time, same conditions.
  2. Week 2: Calculate your weekly average weight. Compare to the prior week. Ignore day-to-day swings from sodium, hydration, or training soreness.
  3. Week 3: If weight is stable (±0.5 lb / ~0.2 kg), your intake is likely near maintenance. If trending up or down, adjust by 100–200 kcal/day and repeat.

Goal Calories & Macros

For fat loss, this calculator offers 10%, 15%, and 20% deficits below estimated maintenance. Structured programs often use reductions in that general spirit, but very low targets may be harder to sustain — adjust based on your own tracking.

Macro preset overview — educational starting points.

Preset

Balanced

Often suits

General use, beginners

Note

Aligns with AMDR ranges (45–65% carbs, 10–35% protein, 20–35% fat)

Preset

Higher Protein

Often suits

Fat loss, muscle retention

Note

Protein set from body weight; supports ISSN 1.6–2.2 g/kg context

Preset

Lower Fat / Lower Carb

Often suits

Food preference, not a requirement

Note

Preference-based; not a strict low-carb protocol

Use the Macro Calculator for a dedicated macro breakdown from any calorie target.

Common Mistakes

  • Overestimating activity — selecting Moderately Active when Lightly Active fits better adds 200–400 kcal/day to your estimate.
  • Treating TDEE as exact — it is a range. Use the ±10% band and calibrate from trends.
  • Changing calories too fast — wait for a 2–4 week trend before adjusting by 100–200 kcal.
  • Guessed body fat with Katch-McArdle — a bad BF% estimate can make this formula less accurate than Mifflin-St Jeor.
  • Ignoring tracking error — weekends, cooking oils, snacks, and alcohol often explain "mysterious" plateaus.
  • Expecting linear weekly loss — water weight, hormonal fluctuations, and sodium cause normal fluctuations.

Myths vs Facts

Myth

3,500 calories always equals 1 pound of fat loss.

Evidence-based view

It is a rough heuristic from early research. Real weight change slows and adapts over time (Hall et al., 2011). Use it for ballpark planning only.

Myth

Eating below BMR puts you in starvation mode and stops fat loss.

Evidence-based view

Energy needs can shift with intake level and weight change. Very low targets may be harder to sustain — adjust based on your own tracking.

Myth

You need exactly 1 g of protein per pound of body weight.

Evidence-based view

ISSN guidance is 1.6–2.2 g/kg for many exercising adults. Total daily intake matters more than hitting a round number.

Myth

TDEE calculators are precise if you pick the right formula.

Evidence-based view

Formula choice matters less than honest activity selection and empirical calibration over 2–3 weeks.

Intended Use & Limitations

This calculator is for informational and journaling purposes only — a personal awareness utility for estimating and logging nutrition numbers. It is not personalized guidance.

Good fit for

Adults estimating calorie starting points for personal tracking

Not designed for

Anyone needing individualized nutrition planning

Good fit for

Adjusting estimates from your own weight logs

Not designed for

Under 18 without appropriate oversight

Good fit for

Learning how BMR, TDEE, and macros relate

Not designed for

Replacing tailored plans built for your specific situation

Good fit for

General fitness and body-composition awareness

Not designed for

Situations that require expert one-to-one assessment

Suggested next steps

BEE Calculator

Seven equations with BEE terminology

Fat-Free Mass Calculator

FFM from body fat %, DEXA & Navy

Lean Body Mass Calculator

Boer, James, Hume when BF% unknown

RMR Calculator

RMR hub with fixed kcal goals & macros

REE Calculator

Compare all 7 resting-energy equations

Maintenance Calculator

Focused view of your maintenance calories

Surplus Calculator

Lean, moderate, and aggressive bulk presets

Deficit Calculator

Compare 250, 500, and 750 kcal deficit options

Activity Level Quiz

Get a realistic activity multiplier recommendation

Methodology

Every formula and coefficient we use, with sources

Frequently Asked Questions

Common questions about TDEE estimation and how this calculator works.

What does TDEE mean?
TDEE stands for Total Daily Energy Expenditure — an estimate of how many calories your body uses over a full 24-hour day. It combines resting energy (BMR), the thermic effect of food, and physical activity including NEAT. Knowing your TDEE gives you a starting point for maintenance, fat loss, or muscle gain planning.
Is TDEE the same as BMR?
No. BMR (Basal Metabolic Rate) estimates energy used at complete rest — breathing, circulation, and organ function. TDEE adds an activity multiplier on top of BMR to approximate total daily energy use including movement, exercise, and digestion. For most people, TDEE is 20–80% higher than BMR depending on activity level.
Which BMR formula should I choose?
Mifflin-St Jeor is the default starting point for most adults and is well-validated in comparative research. Use Revised Harris-Benedict as a cross-check — it may run slightly higher on average. Katch-McArdle is best when you have a reliable body fat percentage from DEXA or calipers; skip it if body fat is guessed.
Is Mifflin-St Jeor better than Harris-Benedict?
Frankenfield et al. (2005) found Mifflin-St Jeor within ~10% of measured resting metabolic rate for roughly 82% of adults in lower body weight ranges — better than many alternatives. Harris-Benedict may overestimate by 50–80 kcal/day on average. Neither is exact for every individual; pick one formula and calibrate from 2–3 weeks of weight trends.
When should I use Katch-McArdle?
Use Katch-McArdle when you have a reasonably accurate body fat measurement — ideally from DEXA, hydrostatic weighing, or calipers. The formula uses lean body mass and ignores age and sex directly. If your body fat estimate is uncertain, Mifflin-St Jeor is usually the better starting choice.
How do I choose my activity level?
Be honest and conservative. Activity multipliers should reflect your total daily movement — not just gym time. A desk job plus 3 gym sessions per week often fits Lightly Active (1.375), not Moderately or Very Active. Take our Activity Level Quiz if unsure, and when in doubt, choose one level lower.
How accurate is a TDEE calculator?
TDEE calculators provide population-level estimates, not precise measurements. BMR formulas may be off by ±10–15% for any individual; activity selection adds another ±200–400 kcal of potential error. Treat the result as a starting range, eat at that level for 2–3 weeks, and adjust by 100–200 kcal based on your actual weight trend.
Why is my real weight not changing at the predicted rate?
Many factors affect scale weight beyond calorie math: water retention, sodium intake, hormonal fluctuations, stress, sleep, and training soreness. Weight also does not change linearly week to week. Track a rolling 7-day average for 3–4 weeks before concluding your estimate is wrong.
Should I eat below my BMR?
Do not use eating below BMR as a general rule or goal. Goal calories below BMR can happen with larger deficits, but extended very low intake may be harder to sustain. If your target feels unsustainably low, consider a smaller deficit and prioritize protein intake in your tracking.
Can I use this calculator for weight loss?
Yes — this calculator can provide an estimated calorie starting point for a deficit below maintenance. Choose a deficit you can sustain (often 250–500 kcal/day below TDEE), track protein intake, and monitor weekly weight averages. These are informational estimates for personal tracking and journaling.
Can I use this calculator for muscle gain?
You can use the surplus options as a reference for eating above maintenance. Small surpluses (+5–10%) are generally easier to control than large ones. Actual muscle gain depends heavily on progressive resistance training, protein intake, sleep, and individual response — not calories alone.
Does this calculator store my data?
No. All calculations run locally in your browser. This site does not send calculator inputs to a server, does not require an account, and does not store your personal data. Optional calibration checklist progress saves only to your device's local storage.

Research & References

Each citation below supports a specific claim on this page. We explain relevance so you can verify the science yourself.

  1. National Academies of Sciences, Engineering, and Medicine — Factors Affecting Energy Expenditure and Requirements. Dietary Reference Intakes for Energy — NCBI Bookshelf, 2023.Defines TDEE components (REE, TEF, PAEE) and explains why population equations cannot capture individual metabolic variation.
  2. Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO — A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247, 1990.Primary source for the Mifflin-St Jeor BMR equation used as the default in this calculator.
  3. Roza AM, Shizgal HM — The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass. Am J Clin Nutr. 1984;40(1):168-182, 1984.Source for the revised Harris-Benedict coefficients — default equation on this calculator page.
  4. McArdle WD, Katch FI, Katch VL — Exercise Physiology: Energy, Nutrition, and Human Performance. Lippincott Williams & Wilkins, 7th edition, 2010.Textbook reference for the lean-body-mass-based Katch-McArdle resting energy estimate.
  5. Frankenfield D, Roth-Yousey L, Compher C — Comparison of Predictive Equations for Resting Metabolic Rate in Healthy Nonobese and Obese Adults. J Am Diet Assoc. 2005;105(5):775-789, 2005.Meta-analysis showing Mifflin-St Jeor within ~10% of measured RMR for ~82% of non-obese and ~70% of obese adults — supports honest accuracy framing.
  6. Chao AM, Tronieri JS, Alamuddin N, Wadden TA — Behavioral Approaches to Obesity Management. Endotext — NCBI Bookshelf, 2026.Supports evidence-aware wording around structured calorie deficits and behavioral weight management.
  7. Institute of Medicine, Food and Nutrition Board — Acceptable Macronutrient Distribution Ranges. Dietary Reference Intakes — summary table (NCBI Bookshelf), 2003.Provides AMDR context (10–35% protein, 20–35% fat, 45–65% carbs) for balanced macro presets.
  8. Jager R, Kerksick CM, Campbell BI, et al. — International Society of Sports Nutrition Position Stand: Protein and Exercise. J Int Soc Sports Nutr. 2017;14:20, 2017.Supports 1.6–2.2 g/kg/day protein ranges for many exercising adults — basis for protein and macro guidance.
  9. Hall KD, Sacks G, Chandramohan D, et al. — Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-837, 2011.Shows weight change is slow and non-linear over time — supports labeling the 3,500 kcal/lb rule as a rough heuristic, not a law.
  10. Dhurandhar NV, Schoeller D, Brown AW, et al. — Energy balance measurement: when something is not better than nothing. Int J Obes (Lond). 2015;39(7):1109-1113, 2015.Documents systematic overreporting of exercise and underreporting of food — supports activity-level conservatism guidance.
  11. Bassett DR Jr, Toth MJ, Poehlman ET — Energy Expenditure Determined by Self-Reported Physical Activity Is Related to Body Fatness. Obes Res. 1999;7(6):567-573, 1999.Shows self-reported activity duration and intensity are unreliable — especially at higher body fat percentages.