TDEE Calculator

Overview

How to use this calculator

1. Enter your current weight in kilograms, height in centimeters, age in years, and select the gender option that corresponds to the Mifflin‑St Jeor constants you want to use.
2. Select the activity multiplier that best matches your typical week, not your most active or least active day—be honest about movement and structured exercise.
3. The calculator computes your BMR via the Mifflin‑St Jeor formula and then multiplies it by the activity multiplier to estimate TDEE.
4. Review your BMR (resting burn) and TDEE (estimated daily burn) values.
5. Use TDEE as an initial reference point for setting calorie targets: below TDEE for fat loss, around TDEE for maintenance, and above TDEE for weight gain or muscle building.
6. Track your weight and performance over several weeks and adjust calories up or down if your real‑world results don’t match the planned direction.

Inputs explained

Weight (kg)

Your body weight in kilograms. If you know your weight in pounds, divide by 2.20462 to convert (for example, 165 lb ÷ 2.20462 ≈ 74.8 kg).

Height (cm)

Your height in centimeters. If you know your height in inches, multiply by 2.54 to convert (for example, 70 in × 2.54 ≈ 178 cm).

Age

Your age in years. BMR typically declines slowly with age as average lean mass and hormonal profiles change.

Gender

Used to choose the appropriate Mifflin‑St Jeor constants. The equation has slightly different offsets for males and females based on average body composition differences.

Activity multiplier

A lifestyle factor from about 1.2 (sedentary) to 1.9 (very active/athlete), representing how much you move and exercise on an average day. Choose the option that best describes your typical weekly routine.

Outputs explained

BMR

Basal metabolic rate in calories per day, estimated by Mifflin‑St Jeor. This is your approximate resting energy expenditure if you did nothing but rest for 24 hours.

TDEE

Total Daily Energy Expenditure in calories per day, equal to BMR multiplied by your activity multiplier. This is your estimated daily burn given your current lifestyle.

When to use it

• Setting calorie targets for weight loss, maintenance, or muscle gain phases based on an estimate of your daily energy needs.
• Estimating daily burn to help with macro planning and portion sizing for long‑term nutrition programs.
• Assessing how upgrades in activity—like adding regular workouts or a more active job—might change your calorie needs.
• Providing a baseline for discussions with a coach or nutritionist when designing a training and nutrition plan.
• Estimating maintenance calories before a cut or bulk to set a reasonable calorie deficit or surplus.
• Re‑calibrating intake after long plateaus or major routine changes (new job, training plan, or lifestyle shift).
• Planning re‑feeds or diet breaks by estimating true maintenance before temporarily increasing calories.
• Estimating daily burn when switching from an office job to a more active role (or vice versa).

Tips & cautions

• Choose the activity multiplier that reflects your average week, not your best training day; overestimating activity is a common reason calorie targets miss the mark.
• Re‑estimate TDEE whenever your weight changes significantly (for example, every 5–10 lb) or when your job, routine, or training volume changes.
• If you use imperial units day to day, convert carefully to metric for input and keep conversions consistent to avoid compounding rounding errors.
• Treat TDEE as a starting point; monitor your weight, measurements, and performance over at least 2–4 weeks before making big adjustments.
• If you’re unsure between two activity levels, start with the lower multiplier (more conservative) and increase if you consistently lose weight faster than expected.
• Pair TDEE estimates with other markers like hunger, energy levels, training performance, and sleep quality—if a calorie target leaves you chronically depleted, it may be worth easing up even if the math suggests it will work.
• Use weekly averages: daily calorie burn fluctuates, but TDEE is meant to represent your typical week over time.
• If you add structured cardio or steps, increase activity slowly and reassess after a few weeks rather than jumping multipliers.
• If you track steps, use them as a consistency check—large step increases usually justify a higher multiplier.
• Pair TDEE with a macro plan: set protein first, then distribute remaining calories between carbs and fats based on preference and training.
• If you track intake, use a 7‑day average rather than single days to judge progress against your TDEE target.
• TDEE is a population-based estimate and does not account for all individual differences in metabolism, body composition, hormonal status, or metabolic adaptations.
• Activity multipliers are broad guidelines; actual energy expenditure can be higher or lower depending on factors such as NEAT (non‑exercise activity thermogenesis) and training specifics.
• Not tailored for children, pregnant or breastfeeding individuals, or those with certain medical conditions; these situations require specialized guidance.
• Does not incorporate body fat percentage or lean mass directly; equations based on lean mass may be more appropriate for some athletic or clinical populations.
• Does not explicitly model TEF or adaptive thermogenesis during prolonged dieting.
• May under‑ or over‑estimate needs for very muscular individuals, older adults, or those with metabolic conditions.

Worked examples

Deep dive

Methodology & assumptions

• Computes BMR using the Mifflin‑St Jeor equation with inputs in kg, cm, and years.
• Applies a user-selected activity multiplier to estimate TDEE (TDEE = BMR × activity).
• Activity multipliers are broad lifestyle categories and should be treated as starting points.
• Results are estimates; adjust based on observed weight and performance trends over time.

Sources

• Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals.Original Mifflin‑St Jeor equation (Am J Clin Nutr. 1990;51:241–247).
• NCI DCCPS — REE‑Mifflin St Jeor equation, Total EE, Physical Activity Level (PAL)Overview of REE and PAL approach for estimating total energy expenditure.

FAQs

Should I use pounds/inches?

Convert to metric for best accuracy. 1 kg = 2.20462 lbs; 1 cm = 0.393701 in.

Does this include exercise calories?

Yes. The activity multiplier represents average exercise volume.

What if my real-world results don’t match the estimate?

That’s normal—TDEE equations are starting points. If your weight is not changing as expected after several weeks, adjust your calorie intake up or down (for example, by 5–10%) and monitor again. Over time you can hone in on a personalized maintenance level.

Can I use this calculator while doing intermittent fasting or specific diets?

Yes. TDEE is about total daily energy, not meal timing or diet style. You can use the estimate as a daily calorie target whether you eat in one meal or several, and whether you follow low‑carb, high‑carb, or other approaches. Just make sure the total intake over the day aligns with your goals and adjust based on actual progress.

Is BMR the same as RMR?

They’re similar but not identical. BMR is measured under stricter conditions (fasted, rested, thermoneutral). Many calculators estimate resting metabolic rate (RMR), which is usually slightly higher. For practical purposes, the difference is small for most users.

How do I choose the right activity multiplier?

Pick the category that matches your average week, including job movement and exercise. If you’re between two options, start with the lower multiplier and adjust based on real‑world results after a few weeks.

Is a small calorie deficit enough for fat loss?

Often yes. A modest deficit (around 5–15% below TDEE) is easier to sustain and can preserve training performance. Use your TDEE as the baseline, then adjust based on progress.

Do I need to recalculate if I lose or gain weight?

Yes. As body weight changes, your BMR and TDEE shift. Recalculate every 5–10 lb (2–5 kg) change or after a major training or lifestyle shift.

Related calculators