Which formula does this calculator use?

Basal Metabolic Rate uses Mifflin–St Jeor. TDEE multiplies that BMR by a standard activity factor (sedentary through extra active). Other equations exist; this page documents the one we implement.

Is this medical or dietary advice?

No. Outputs are informational estimates for education and rough planning. They are not a diagnosis, prescription, or substitute for care from a physician, registered dietitian, or other qualified professional.

How accurate is TDEE for one person?

Population equations can miss an individual by several hundred kilocalories. Genetics, lean mass, hormones, sleep, illness, and non-exercise activity all matter. Use trends over weeks, not a single estimate, to guide changes.

Should I eat exactly TDEE every day to maintain weight?

Treat TDEE as a center point, not a rigid daily quota. Appetite, sodium, glycogen, and measurement noise move day-to-day weight. Adjust based on multi-week averages and professional context if you have health conditions.

What about athletes, pregnancy, illness, or adolescents?

Special populations need tailored energy guidance. This general adult calculator is not designed for pregnancy, lactation, eating-disorder care, pediatric growth, or elite sport nutrition without clinician oversight.

How does Mifflin–St Jeor differ from Katch–McArdle?

Mifflin–St Jeor uses sex, age, weight, and height. Katch–McArdle hinges on lean body mass and needs a reliable body-fat estimate. We use Mifflin–St Jeor here because it fits common height–weight inputs.

Which activity level should I pick?

Match your usual weekly pattern. Desk work with three gym sessions often lands between light and moderate. If unsure, calculate two neighboring levels and see the range rather than pretending one label is perfect.

Can I use TDEE for weight loss or muscle gain?

People often use maintenance estimates as a reference, then create a deficit or surplus. The size and speed of that change should be individualized—especially when medical conditions, medications, or disordered eating history are present.

Do watches and treadmill calorie readouts replace TDEE?

No. Device burn estimates vary widely and usually cover only part of the day. Adding them on top of a full TDEE can double-count activity. Prefer consistent dietary and weight data over gadget precision theater.

Why does biological sex appear in the inputs?

Mifflin–St Jeor uses different constants for the adult male and female equation forms published in the literature. The field is a equation requirement, not a full assessment of gender identity or medical history.

What units should I use for weight and height?

Use the units the form accepts and convert carefully if your scale is imperial while the equation expects metric. A 2.2 factor mix-up (lb vs kg) can swing BMR by a large margin.

Is health data stored on your servers?

No. BMR and TDEE computations run locally in your browser for this tool.

BMR & TDEE Calculator

BMR estimates the energy your body would need at complete rest; TDEE scales that estimate by how active you usually are across a typical week. This calculator uses the widely cited Mifflin–St Jeor equation plus standard activity multipliers to give ballpark maintenance calories for adults. Treat the output as an educational starting point for meal planning conversations—not a personalized medical prescription. Individual metabolism, health conditions, medications, and training history can shift needs by hundreds of calories. Recalculate when weight or routine change, and involve a qualified clinician or registered dietitian for clinical goals.

Age (years)Height (cm)Weight (kg)

Activity level

Estimated BMR

-- kcal/day

Estimated TDEE

-- kcal/day

Informational only; verify critical results independently.

How to use

Enter the biological sex the Mifflin–St Jeor equation expects, along with age in years, weight, and height in the units the form supports.
Choose the activity level that best describes most weeks—not your peak training day or an unusual sedentary holiday.
Review BMR first: it is the resting component before activity multipliers are applied.
Then read TDEE: BMR multiplied by the selected activity factor to approximate total daily energy expenditure.
If your job is mostly sitting but you train hard outside work, test nearby activity levels and see how TDEE shifts rather than forcing one imperfect label.
Use TDEE only as a maintenance-oriented estimate; deliberate deficits or surpluses belong in a plan shaped with professional guidance.
Re-run the calculator after meaningful weight change, a new job activity profile, or a lasting shift in training volume.
Prefer consistent measurement conditions (similar scale, similar clothing, similar time of day) so inputs stay comparable week to week.
Remember that wearables and gym machines report their own calorie burn models; do not add those numbers on top of TDEE without understanding double-counting risk.
If results feel extreme for your lived hunger, energy, or weight trend, treat that mismatch as a signal to reassess inputs—and seek personalized advice rather than forcing the estimate.

Examples

Male, 80 kg, 180 cm, age 25, moderately active: BMR ≈ 1,805 kcal; TDEE ≈ 2,798 kcal (×1.55).
Female, 60 kg, 165 cm, age 30, light activity: BMR ≈ 1,320 kcal; TDEE ≈ 1,815 kcal (×1.375).
Same person sedentary (×1.2) vs very active (×1.725) can change TDEE by roughly 40%+ of BMR—activity choice matters.
Female, 70 kg, 165 cm, age 28, very active: BMR ≈ 1,430 kcal; TDEE ≈ 2,467 kcal (×1.725).
Male, 90 kg, 175 cm, age 40, sedentary: BMR ≈ 1,799 kcal; TDEE ≈ 2,159 kcal (×1.2).
Add 10 kg at fixed height and age: BMR rises because Mifflin–St Jeor includes a weight term—TDEE rises by the same multiplier.
Compare age effects: holding other inputs fixed, older age slightly lowers estimated BMR under Mifflin–St Jeor.
Light vs moderate on identical stats: moving from ×1.375 to ×1.55 raises TDEE by about 12.7% of BMR.
Rough worksheet check: if a printed BMR is far from Mifflin–St Jeor given the same sex, age, weight, and height, recheck unit conversions (lb ↔ kg, in ↔ cm).
Maintenance experiment framing: start near estimated TDEE, track multi-week weight trend, then adjust—never treat a single day as proof.

FAQ

Which formula does this calculator use?: Basal Metabolic Rate uses Mifflin–St Jeor. TDEE multiplies that BMR by a standard activity factor (sedentary through extra active). Other equations exist; this page documents the one we implement.
Is this medical or dietary advice?: No. Outputs are informational estimates for education and rough planning. They are not a diagnosis, prescription, or substitute for care from a physician, registered dietitian, or other qualified professional.
How accurate is TDEE for one person?: Population equations can miss an individual by several hundred kilocalories. Genetics, lean mass, hormones, sleep, illness, and non-exercise activity all matter. Use trends over weeks, not a single estimate, to guide changes.
Should I eat exactly TDEE every day to maintain weight?: Treat TDEE as a center point, not a rigid daily quota. Appetite, sodium, glycogen, and measurement noise move day-to-day weight. Adjust based on multi-week averages and professional context if you have health conditions.
What about athletes, pregnancy, illness, or adolescents?: Special populations need tailored energy guidance. This general adult calculator is not designed for pregnancy, lactation, eating-disorder care, pediatric growth, or elite sport nutrition without clinician oversight.
How does Mifflin–St Jeor differ from Katch–McArdle?: Mifflin–St Jeor uses sex, age, weight, and height. Katch–McArdle hinges on lean body mass and needs a reliable body-fat estimate. We use Mifflin–St Jeor here because it fits common height–weight inputs.
Which activity level should I pick?: Match your usual weekly pattern. Desk work with three gym sessions often lands between light and moderate. If unsure, calculate two neighboring levels and see the range rather than pretending one label is perfect.
Can I use TDEE for weight loss or muscle gain?: People often use maintenance estimates as a reference, then create a deficit or surplus. The size and speed of that change should be individualized—especially when medical conditions, medications, or disordered eating history are present.
Do watches and treadmill calorie readouts replace TDEE?: No. Device burn estimates vary widely and usually cover only part of the day. Adding them on top of a full TDEE can double-count activity. Prefer consistent dietary and weight data over gadget precision theater.
Why does biological sex appear in the inputs?: Mifflin–St Jeor uses different constants for the adult male and female equation forms published in the literature. The field is a equation requirement, not a full assessment of gender identity or medical history.
What units should I use for weight and height?: Use the units the form accepts and convert carefully if your scale is imperial while the equation expects metric. A 2.2 factor mix-up (lb vs kg) can swing BMR by a large margin.
Is health data stored on your servers?: No. BMR and TDEE computations run locally in your browser for this tool.

Formula / Method

Mifflin–St Jeor BMR (kcal/day): men 10×kg + 6.25×cm − 5×age + 5; women 10×kg + 6.25×cm − 5×age − 161. TDEE ≈ BMR × activity factor (commonly ~1.2 sedentary through ~1.9 extra active). Example factors vary slightly by source; use the labels shown in the tool.

Assumptions & Limitations

Informational only—not medical advice. Assumes adult inputs suited to Mifflin–St Jeor and a single weekly activity category. Does not measure labs, body composition, hormones, or illness. Estimates can err by hundreds of kcal; clinical or therapeutic nutrition requires a qualified professional.

Related guides

BMI and Health Metrics: What They Mean and When to Use Them
Understand adult BMI categories, limits of the metric, and how BMR/TDEE estimates work—informational tools, not medical advice.

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Last updated: 2026-07-13

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