TDEE Calculator: Find Your Maintenance Calories

If you’ve ever asked, “How many calories should I eat?” you’re really asking for a TDEE calculator—a way to estimate how many calories you burn on an average day.

TDEE (total daily energy expenditure) is your total calories burned per day from rest, movement, and digestion.

Definition (and how to use it): A TDEE calculator estimates your maintenance calories—the calories you’d eat to keep your weight stable—using a simple model: TDEE ≈ resting calories (REE) × activity multiplier.

Many online calculators call this “BMR,” but for most people the output is closer to resting metabolic rate / resting energy expenditure (RMR/REE). BMR is usually measured under stricter conditions, while RMR/REE is measured in a more practical “resting” state (review on BMR vs RMR measurement protocols, 2023).

A typical TDEE calculator uses your age, biological sex, height, weight, and activity level. Some tools also let you add body fat % (optional, but helpful if you have a good measurement).

Use the calculator below to estimate your maintenance calories. Then keep reading to learn which formula to use, how to pick an activity multiplier, and how to turn your TDEE into a cutting, maintenance, or bulking plan.

TDEE Calculator

Enter your stats and choose an activity level. The result is your estimated maintenance calories (TDEE). From there, you can create a deficit to lose fat or a small surplus to gain.

If you don’t see the calculator tool, use the “manual” method below.

Calculator inputs (what you’ll enter)

• Age (years)
• Biological sex
• Height (ft/in or cm)
• Weight (lb or kg)
• Activity level (from the multiplier table below)
• Optional: Body fat % (enter as a percent, e.g., 25)

Calculator math (what it will do)

1. Estimate resting calories (REE) using Mifflin–St Jeor by default.

2. If you enter body fat %, the calculator can optionally switch to a lean-mass-based estimate (Katch–McArdle):

• Fat-free mass (FFM) = weight(kg) × (1 − body fat%/100)
• REE ≈ 370 + 21.6 × FFM(kg)

Unit note: Katch–McArdle uses kilograms. If your weight is in pounds, convert with lb ÷ 2.2046 = kg.

3. Multiply resting calories by your selected activity multiplier to estimate TDEE.

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Quick glossary (so the rest is painless)

Online calculators often mix these terms. Here’s the simple version:

• BMR (basal metabolic rate): calories your body would burn at complete rest under very strict lab conditions.
• RMR/REE (resting metabolic rate / resting energy expenditure): calories you burn at rest under more “real world” conditions; most online “BMR” calculators are really estimating this.

In this guide, we’ll mostly say resting calories (REE).

Terminology note: You may see DXA written as DEXA online. Same test—different spelling. In this article, we’ll stick with DXA.

FFM vs. LBM note: Many sources use fat-free mass (FFM) and lean body mass (LBM) somewhat interchangeably in calorie equations. Here, we’ll use FFM for consistency.

Medical note: This article is for general education only and isn’t medical advice. If you’re pregnant, under 18, have a history of disordered eating, or have a medical condition or medication that affects weight/appetite, get personalized guidance from a qualified clinician.

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What a TDEE calculator is actually doing

Most tools use a “two-step” estimate:

1. Estimate resting calories (REE) with an equation.
2. Multiply by an activity multiplier to estimate total burn.

In calculator form:

TDEE ≈ REE × activity multiplier

Why it’s an estimate: in real life, your “non-resting” burn is a bundle of things—intentional exercise, day-to-day movement, and the thermic effect of food (TEF) (calories used to digest food). Many consumer calculators roll these pieces into the activity multiplier so you don’t have to add them separately.

Day-to-day movement is often called NEAT (non-exercise activity thermogenesis)—calories from walking, chores, fidgeting, etc. Since activity and eating patterns change day to day, the final TDEE number is a best estimate, not a perfect measurement.

(For a more technical breakdown of TEE components—REE, TEF, and activity—see Dietary Reference Intakes for Energy: Factors affecting energy expenditure and requirements (National Academies).)

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How to calculate your TDEE (step-by-step)

You can use these steps with any TDEE calculator—or do it manually with a calculator app.

Step 1: Estimate resting calories (REE)

Most calculators estimate REE (resting energy expenditure), then build up to TDEE.

Option A: Mifflin–St Jeor (common default)

The Mifflin–St Jeor equation is widely used in online tools.

It was derived from 498 healthy adults using indirect calorimetry (a lab method that estimates energy use from breathing gases) (Mifflin et al., 1990).

A newer validation study in older adults with obesity found that common equations (including Mifflin–St Jeor) varied in accuracy, with none consistently accurate enough for all individuals—highlighting why you should treat any calculator output as a starting point, not a diagnosis (validation of REE equations in older adults with obesity, 2023).

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

Option B: Katch–McArdle (best if you have accurate body fat % / FFM)

Katch–McArdle estimates resting burn from fat-free mass (FFM) instead of total body weight.

A commonly used form is:

• REE ≈ 370 + 21.6 × FFM(kg)

This equation form is referenced in research comparing predictive equations to indirect calorimetry, including a study listing Katch–McArdle = 370 + 21.6 × LBM (kg) (Raval et al., 2017).

Why that’s useful: fat-free mass (FFM) is consistently one of the strongest predictors of resting energy expenditure. For example, a study in healthy adults found FFM-related measures showed the strongest association with REE (Suckling et al., 2024).

If you want a deeper guide to resting-calorie equations (and when to use each), see BMR calculator: using it for metabolic insights.

Step 2: Multiply by your activity factor

Most calculators then apply an “activity multiplier.” You’ll often see this described as an “activity level” dropdown.

In research settings, a related concept is physical activity level (PAL).

PAL is often defined as total energy expenditure ÷ resting energy expenditure in energy requirement guidance (Dietary Reference Intakes for Energy: Factors affecting energy expenditure and requirements (National Academies)).

A major FAO/WHO/UNU consultation groups adult lifestyles into three broad PAL ranges:

• Sedentary/light: PAL 1.40–1.69
• Active/moderately active: PAL 1.70–1.99
• Vigorous/vigorously active: PAL 2.00–2.40

(FAO: Human energy requirements).

Bridge (PAL vs. calculator multipliers): Consumer TDEE calculators typically use a simple “resting calories × multiplier” convention that’s inspired by PAL concepts, but it doesn’t map perfectly to FAO PAL ranges or definitions.

For example, Medscape’s Mifflin–St Jeor calculator lists 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderate), 1.725 (active), and 1.9 (very active) (Medscape: Mifflin–St Jeor equation + activity factors).

Use the table below as the common online-calculator convention, and then calibrate based on your real-world trend.

Quick examples (to help you pick)

• 1.2 (Sedentary): desk job + low daily steps + workouts are rare.
• 1.375 (Light): desk job + 1–3 workouts/week + you’re still mostly sitting outside workouts.
• 1.55 (Moderate): 3–5 workouts/week + you also move a decent amount most days (walks/errands/steps).
• 1.725 (Very active): frequent training and/or a job where you’re on your feet a lot.
• 1.9 (Extra active): hard training most days plus very high daily movement or a physically demanding job.

Step 3: Your TDEE

TDEE ≈ REE × activity multiplier

That’s your estimate for “maintenance calories.”

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How a DXA scan can make your TDEE estimate more accurate

A TDEE calculator isn’t “wrong” just because it’s an estimate—your body’s true daily burn is hard to measure precisely in real life.

A practical way to improve the starting estimate is to use a resting-calorie equation that incorporates fat-free mass (FFM), since FFM is a strong predictor of resting energy expenditure (Suckling et al., 2024).

Why body fat % matters for TDEE

Two people can weigh the same but have very different fat-free mass (FFM). Knowing your body fat % helps you estimate REE with a lean-mass-based equation (like Katch–McArdle) instead of relying only on scale weight.

Why DXA can be a strong way to get body fat %

DXA is widely used in research and clinical settings for body composition assessment (Shepherd et al., 2017).

It can also be a useful reference point when you want to sanity-check at-home estimates (like bioelectrical impedance / “smart scale” readings). A large retrospective study found wide limits of agreement between BIA and DXA at the individual level (PLOS ONE study: DXA vs. BIA body composition agreement across BMI categories (2018)).

If you want the deeper “what does the scan measure?” walkthrough, see Body fat percentage DXA scan: what it means and why it matters.

Practical: how to use a DXA result inside a TDEE calculator

1. Get your body fat % from a DXA scan.

2. Convert weight to kilograms if needed:

• kg = lb ÷ 2.2046

3. Calculate fat-free mass (FFM):

• FFM = weight(kg) × (1 − body fat%/100)

Example: 180 lb at 25% body fat → weight ≈ 81.6 kg → FFM ≈ 81.6 × (1 − 25/100) = 61.2 kg

4. Plug FFM into Katch–McArdle:

• REE ≈ 370 + 21.6 × 61.2 ≈ 1,692 kcal/day

5. Multiply by an activity factor to estimate TDEE.

Important: A DXA scan can improve the inputs (body fat % / fat-free mass) that drive a resting-calorie equation, but it does not directly measure your TDEE.

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About “sex” inputs (quick clarification)

Most TDEE calculators include a “sex” field because many classic calorie equations were built using biological sex categories.

If you’re on hormone therapy or you’re unsure which input best matches your current physiology, talk with a clinician. (This article can’t provide clinical guidance.)

A practical approach some people use is to run both options to create a range, then calibrate using your 2–3 week trend (see the section below).

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Your calorie targets: maintenance, cutting, and bulking

Once you have an estimated TDEE, you can turn it into a goal.

Maintenance calories

• Maintenance ≈ your estimated TDEE

Cutting calories (fat loss)

Most sustainable fat loss is gradual. The CDC notes that people who lose weight at a steady pace—about 1–2 pounds per week—are more likely to keep it off (CDC: Steps for Losing Weight).

One common way to start is a moderate deficit that supports that pace. For example, Mayo Clinic describes that losing ~1–2 lb/week typically requires a daily calorie deficit of about 500–750 calories (Mayo Clinic weight-loss strategies).

Safety note: a specific deficit size isn’t appropriate for everyone, and more aggressive deficits can be risky for some people. If you’re unsure, get individualized guidance from a clinician or registered dietitian.

If you’re not sure whether your deficit is mostly “fat loss” or “weight loss,” this helps: Fat loss vs. weight loss: key differences and tracking.

Bulking calories (muscle gain)

For muscle gain, the goal is usually a small, controlled surplus.

In resistance-trained lifters, a study compared maintenance vs 5% vs 15% energy surpluses:

• Larger surpluses tended to drive faster body-mass gain.
• Faster body-mass gain tended to predict larger increases in skinfold thickness (more fat gain).

Muscle and strength benefits were smaller and more variable across individuals (Helms et al., 2023).

Practical takeaway: If you’re already lifting consistently, start near the low end (around ~5% above maintenance) and adjust.

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Macro calculator: a simple way to set protein, carbs, and fat

If you want a full macro walkthrough (plus app recommendations), use: Tracking macros: a 5-minute beginner’s guide.

Step 1: Set protein (grams, not percentages)

For healthy, exercising adults, the International Society of Sports Nutrition (ISSN) position stand suggests total daily protein around 1.4–2.0 g/kg/day for most exercisers (ISSN position stand, 2017).

More recently, systematic reviews/meta-analyses in healthy adults find that higher daily protein intake supports small additional gains in lean body mass and strength during resistance training, with benefits observed in some groups at intakes around ≥1.6 g/kg/day (Tagawa et al., 2022; protein intake + resistance training systematic review/meta-analysis, 2022).

Step 2: Choose a fat range (AMDR)

For adults, Canada’s DRI table lists AMDR ranges of 20–35% of calories from fat, 45–65% from carbohydrate, and 10–35% from protein (Health Canada: DRI reference values for macronutrients).

Macro templates (percent of calories)

These are flexible starter templates (not personalized medical nutrition advice). They sit within adult AMDR guardrails from the DRI tables (Health Canada, DRI macronutrient ranges).

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Worked example (so you can sanity-check your calculator)

Let’s say your calculator estimates:

• TDEE: 2,500 kcal/day

Here are three simple targets:

• Maintenance: 2,500 kcal
• Cut: 1,900–2,000 kcal (a 500–600 kcal deficit)
• Lean bulk: ~2,625 kcal (a 5% surplus)

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How to make your TDEE estimate more accurate (without overthinking it)

1) Treat the calculator as a starting point

Prediction equations can be off for individuals, even when they’re widely used.

(Example: a validation study in older adults with obesity found common REE equations varied in accuracy.)

2) Run it consistently for 2–3 weeks

Keep calories and habits reasonably consistent and track:

• a daily weigh-in trend (weekly average)
• waist measurement trend
• training performance

3) Adjust based on the trend

A non-clinical rule of thumb many people use: if your weekly trend isn’t moving the way you want, make a small adjustment and hold long enough to see a new trend (often around 1–2 weeks). If you’re unsure how to adjust safely, work with a clinician or registered dietitian.

If you’re using a structured weight-management program, the American Diabetes Association’s Standards of Care note that high-frequency lifestyle interventions often aim for an energy deficit on the order of 500–750 kcal/day (ADA Standards of Care, 2023).

Safety note: If you have a medical condition, take appetite/weight-affecting medications, or have a history of disordered eating, work with a clinician or registered dietitian for personal targets.

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Track body composition (so you know what the scale change means)

A DXA scan can help you understand whether you’re changing fat mass vs. lean mass—not just body weight. DXA is widely used in research and clinical settings for body composition assessment (Shepherd et al., 2017).

Why consistent prep matters: DXA-based body composition outputs can shift with things like hydration and recent food/fluids, because “lean mass” includes body water. BodySpec’s accuracy guide highlights hydration and food timing as key factors for reproducible results (DEXA scan accuracy guide).

If you’re scanning for trend tracking (not a one-off curiosity), it’s also smart to avoid “weird” prep right before your scan. For example, research in active men found that exercise-induced dehydration and carbohydrate loading (glycogen supercompensation) produced large apparent swings in DXA-measured lean tissue mass without changing fat mass (Elliot-Sale et al., 2017).

For a deeper dive into how DXA works (and what your report includes), see How a DXA scan works.

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FAQ

What does TDEE stand for?

TDEE stands for total daily energy expenditure—the total calories you burn per day when you add resting burn plus all movement.

Which TDEE formula is most accurate?

There isn’t one “best” equation for everyone. Common equations can be off depending on population and individual variability. If you have an accurate body fat % (for example, from DXA), a lean-mass-based option like Katch–McArdle can be a better starting point.

What activity level should I choose?

Use the activity multiplier table above as a starting point—then validate it against your real-world trend.

If you’re between two options, many people do best choosing the lower multiplier first and watching the 2–3 week trend (weekly weight average, waist trend, and training performance). If maintenance calories are too high or too low, adjust and re-check.

How often should I recalculate my TDEE?

A common heuristic is to re-check your estimate any time your body weight meaningfully changes or your activity level changes for multiple weeks—then calibrate based on your 2–3 week trend.

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Bottom line

A TDEE calculator is the fastest way to get an evidence-based calorie starting point for maintenance, fat loss, or muscle gain.

If you want a more personalized estimate, a DXA scan can improve the inputs (body fat % / fat-free mass) that drive resting-calorie equations—and it helps you verify whether your plan is changing fat mass vs. lean mass.

• Book a scan: BodySpec booking
• Learn what to expect: How a DXA scan works
• Or browse: Find a DXA scan near you