What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is the energy your body uses at complete rest — breathing, circulation, cell repair. TDEE (Total Daily Energy Expenditure) includes BMR plus all activity: digesting food, walking, exercising, fidgeting, etc. TDEE is always higher than BMR. For weight management, TDEE is the relevant number.

Which BMR formula is the best fit?

The Mifflin-St Jeor equation is one of the most studied options for adults and is commonly used in nutrition practice. The Katch-McArdle formula can be a useful comparison if you know your body fat percentage, since it accounts for lean body mass directly. This calculator shows both when body fat is provided.

Why does the calculator show a range?

Your actual TDEE fluctuates daily based on NEAT (non-exercise activity thermogenesis) — the calories burned through fidgeting, walking, posture, and other unconscious movements. NEAT can vary widely between days. The range reflects that reality and helps you understand that maintenance is a zone rather than a single number.

How do I validate my maintenance calories?

Eat at the estimated TDEE for 2–4 weeks while weighing yourself daily at the same time (morning, fasted). Calculate weekly averages. If the average is stable (±0.5 lb), you have a good maintenance reference. If trending down, add 100–200 kcal. If trending up, subtract 100–200 kcal.

Does metabolism slow with age?

Yes, but less than commonly believed. BMR decreases over time partly because body composition and activity change. Resistance training can help offset some of the decline by maintaining muscle mass.

Should I eat the same calories every day?

Not necessarily. Some people prefer calorie cycling: eating more on training days and less on rest days, while keeping the weekly average at maintenance. This can feel more natural for many people. What matters for weight maintenance is the weekly average.

Maintenance Calories Calculator

Estimate your maintenance calorie level (TDEE) with multiple methods. Includes NEAT variation ranges and macro planning references.

Weight

lbs

Height

Age

yrs

Body Fat (optional)

Sex

Activity Level

Units

Your Maintenance Calories (TDEE)

2,728.00

kcal/day (range: 2,401.00 – 3,055.00)

Mifflin-St Jeor BMR

1,760.00 kcal

Standard equation

NEAT Range

±327.00 kcal

Daily variation from activity

Weekly Total

19,096.00 kcal

Weekly maintenance budget

TDEE Component Breakdown

BMR 65%

NEAT 16%

BMR: ~1,760.00 kcal (65%) — Breathing, circulation, cell repair

NEAT: ~436.00 kcal (16%) — Walking, fidgeting, daily movement

TEF: ~273.00 kcal (10%) — Digesting and processing food

EAT: ~246.00 kcal (9%) — Structured exercise

Calorie Targets by Goal

Goal	Daily Calories	Adjustment	Expected Rate
Fat Loss (moderate)	2,228.00 kcal	-500.00 kcal	~0.5 kg/wk loss
Fat Loss (mild)	2,478.00 kcal	-250.00 kcal	~0.25 kg/wk loss
Maintenance	2,728.00 kcal	0.00 kcal	Weight stable
Lean Bulk	2,978.00 kcal	+250.00 kcal	~0.25 kg/wk gain
Bulk	3,228.00 kcal	+500.00 kcal	~0.5 kg/wk gain

Maintenance Macros

Protein

127g

508.00 kcal (19%)

Carbs

377g

1,508.00 kcal (55%)

Fat

79g

711.00 kcal (26%)

Pro Tip: The most accurate way to find your maintenance calories is to track your weight and intake for 2–4 weeks. If your weekly average weight is stable, your average intake equals your true TDEE. Calculator estimates are starting points with ±10% accuracy.

Planning notes, formulas, and examples

About the Maintenance Calories Calculator

Maintenance calories, or Total Daily Energy Expenditure (TDEE), are the calories you need to roughly hold body weight steady. That makes maintenance the reference point for cutting, bulking, or setting a recomposition plan.

TDEE includes basal metabolic rate, the thermic effect of food, non-exercise activity, and formal exercise. Non-exercise activity varies the most from person to person, which is why any calculator output should be treated as a starting estimate rather than an exact intake.

This page uses the Mifflin-St Jeor equation and gives a maintenance range that can be refined with a few weeks of real weight-trend data.

When This Page Helps

This calculator is useful when you need a starting maintenance estimate before setting a deficit or surplus. A range is often more practical than a single number because daily movement, appetite, and training volume do not stay perfectly constant.

How to Use the Inputs

Enter your weight, height, age, and sex.
Select your general activity level.
Optionally enter body fat percentage for a lean-mass-adjusted estimate.
Review your estimated TDEE and its component breakdown.
Use the NEAT range to understand daily variation.
Track your weight for 2-4 weeks eating at the estimated level to validate.

Formula used

BMR (Mifflin-St Jeor):
• Male: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
• Female: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

BMR (Katch-McArdle, if BF% known):
370 + 21.6 × Lean Body Mass (kg)

TDEE = BMR × Activity Factor
Activity Factors: Sedentary 1.2, Light 1.375, Moderate 1.55, Very Active 1.725, Extreme 1.9

NEAT Range: TDEE ± 10–15% (represents daily variation)

Example Calculation

Result: ~2,530 kcal/day (range: 2,280–2,780)

A 30-year-old male, 175 lbs (79.4 kg), 5'10" (178 cm), moderately active. Mifflin-St Jeor BMR: 1,748 kcal. Katch-McArdle BMR (using 18% BF, LBM = 65.1 kg): 1,776 kcal. Average BMR: ~1,762. TDEE at 1.55 activity: ~2,530 kcal. NEAT variation range: 2,280–2,780 kcal. These are your maintenance calories — eat here for 2 weeks, track weight, and adjust.

Tips & Best Practices

No calculator is perfectly accurate. Use the estimate as a starting point and adjust based on actual weight changes over 2–4 weeks.
If your weight is stable over 2+ weeks, you have a stronger maintenance reference than the initial estimate alone.
NEAT can vary by 500+ kcal/day between your most and least active days. Weekend vs. weekday patterns matter.
Body fat percentage input improves accuracy because muscle is more metabolically active than fat tissue.
Recalculate your maintenance calories every time you gain or lose 5+ kg, as your TDEE changes with your weight.
Sleep deprivation can reduce NEAT by 5–20%, effectively lowering your maintenance calories.

The Components of TDEE

Your total daily energy expenditure breaks down into four components. BMR accounts for the largest share and powers basic life functions. TEF (thermic effect of food) uses energy to digest, absorb, and process food. NEAT is the wildcard: it includes all non-exercise movement and can vary substantially between people. EAT (exercise) is often the smallest component for most people.

Why NEAT Matters

A 30-minute gym session may burn 150–300 kcal, but NEAT accumulated over waking hours can easily reach several hundred calories more or less depending on the person and the day. That is why daily step count and general movement can influence TDEE as much as formal training for many people.

Practical Application

Use your maintenance calories as a reference point for all goals. For fat loss, many people start by subtracting a moderate amount of calories. For lean muscle gain, a smaller surplus is often used. For body recomposition, some people stay near maintenance with higher protein intake. Recalculate every 4–8 weeks as your weight changes, since body size shifts the estimate over time.

Sources & Methodology

Last updated: March 28, 2026

Methodology

This page estimates resting energy expenditure with Mifflin-St Jeor, optionally compares it with Katch-McArdle when body-fat percentage is supplied, and multiplies the result by the selected activity factor to estimate TDEE. The maintenance range is intentionally broad because NEAT, training load, and day-to-day activity can shift actual expenditure away from the midpoint. The output is a planning reference, not a clinical metabolism measurement.

Sources

A new predictive equation for resting energy expenditure in healthy individuals (PubMed / American Journal of Clinical Nutrition) — Original Mifflin-St Jeor equation source.
Measurement of the components of nonexercise activity thermogenesis (PubMed / American Journal of Physiology-Endocrinology and Metabolism) — Reference for NEAT as a variable component of daily energy expenditure.
Resting Energy Expenditure and Body Composition in Overweight Men and Women Living in a Temperate Climate (PubMed) — Validation study showing predictive-equation accuracy varies across populations.

Frequently Asked Questions

BMR (Basal Metabolic Rate) is the energy your body uses at complete rest — breathing, circulation, cell repair. TDEE (Total Daily Energy Expenditure) includes BMR plus all activity: digesting food, walking, exercising, fidgeting, etc. TDEE is always higher than BMR. For weight management, TDEE is the relevant number.