TDEE & Calorie Calculator
Estimate your TDEE with the Mifflin-St Jeor resting-energy equation (1990) and a 1.2–1.9 activity multiplier, plus goal calories and a protein/carb/fat split. Metric and imperial. An estimate, not medical advice.
TDEE & Calorie Calculator Tool
Disclaimer: TDEE estimates are general guides based on standard formulas (Mifflin–St Jeor). Individual metabolic rates vary substantially. Consult a healthcare professional or registered dietitian for personalised guidance.
How to Use the TDEE Calculator
Enter your details
Select your unit system, then enter age, gender, height, and weight. Imperial users enter height in feet and inches. The equation is for adults: ages 18 to 100 are accepted, with a note outside the 19 to 78 range it was built on.
Choose your activity level
Pick the option that best matches your average week, not your best one. The five factors are a calculator convention rather than a measurement, so treat the choice as a first guess you will correct from your weight.
Set your goal
Lose Weight subtracts 500 kcal/day — about 0.45 kg a week at first by the 3,500-kcal-per-pound rule of thumb, slowing after that. Gain Muscle adds 300 kcal, another rule of thumb. Maintain keeps you at TDEE. If a loss target falls under 1,200 kcal a day, the result says so: NICE keeps diets that low for specialist services.
Read your calorie and macro targets — live
There's no button to press: your TDEE, goal calories and the protein/carbs/fat ring update as you type or switch a toggle. The four macro cards give daily gram targets to track in any food app, and you can share a link that reopens the tool with your figures.
Understanding Your Calorie Needs — The Science Behind TDEE
BMR vs TDEE: What Is the Difference
Your Basal Metabolic Rate (BMR) is the energy your body spends at complete rest to sustain basic life functions — breathing, circulating blood, regulating temperature, keeping organs running. It is the largest single component of daily expenditure: depending on age and lifestyle, 45 to 70 percent of the total, in the words of the FAO/WHO/UNU expert consultation (Human Energy Requirements, 2004). Strictly, Mifflin-St Jeor predicts resting energy expenditure, measured at rest after an overnight fast; calculator pages use the two terms interchangeably and this one follows that convention.
Your Total Daily Energy Expenditure (TDEE) adds to that the energy of physical activity, of digesting food (the same consultation puts it at about 10 percent of BMR over a day on a mixed diet) and of all the incidental movement of a day — walking to the bus, typing, fidgeting. TDEE is the figure that matters for body weight: eat below it to lose, at it to maintain, above it to gain. This calculator estimates it as Mifflin-St Jeor × an activity multiplier from 1.2 (sedentary) to 1.9 (extremely active).
Those five multipliers are a calculator convention. They are not in Mifflin's paper, and they do not line up with the physical activity levels FAO/WHO/UNU use, which run from 1.40–1.69 for a sedentary or light-activity lifestyle through 1.70–1.99 for an active one to 2.00–2.40 for a vigorous one (Table 5.3). The same report gives 1.21 for people who are totally inactive and dependent on others, which is close to this ladder's bottom rung. So the "Sedentary" setting is cautious for someone with a desk job, and the result is a starting estimate to check against your weight, not a measurement.
Three resting-energy equations are in common use. The Harris-Benedict equation (1919, re-evaluated by Roza and Shizgal in 1984) was the standard for decades but was built on a small, early-twentieth-century sample. The Katch-McArdle formula is popular with athletes because it works from lean body mass, which means it needs a measured body-fat percentage. The Mifflin-St Jeor equation (1990) was derived by indirect calorimetry in 498 healthy US adults, normal-weight and obese, and in that sample the older Harris-Benedict equations overestimated measured resting expenditure by about 5% (Am J Clin Nutr 1990;51(2):241-247). A 2005 systematic review for the American Dietetic Association compared the four equations most used in practice and found Mifflin-St Jeor the most reliable, predicting resting metabolic rate within 10% of measurement in more non-obese and obese adults than any other (Frankenfield et al., J Am Diet Assoc 2005;105(5):775-789). That is why this calculator uses it: resting kcal/day = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 for men, or − 161 for women.
Two cautions apply to a Southeast Asian reader. First, the equation was derived in the United States, and the 2005 review noted that ethnic minorities were under-represented both in the development of the predictive equations and in the studies validating them — so an individual error larger than the population average is possible. Second, the activity multiplier is the loosest part of the estimate: it is a self-assessment against a ladder that is itself a convention, and it is easy to land a level out in either direction. Treat the result as a starting estimate, weigh yourself weekly, and adjust the target by 100–200 kcal after two to four weeks of real data. The number that matters is the one your scale confirms, not the one the formula prints.
Why Asians Need Different Calorie Targets
Body composition differs between populations at the same BMI. Deurenberg-Yap and colleagues measured Singaporean Chinese, Malays and Indians and found a higher body-fat percentage than Caucasians at the same BMI (Int J Obes 2000;24(8):1011-1017). This is part of why the WHO Expert Consultation of 2004 published lower public-health action points for Asian populations — 23.0 and 27.5 — while retaining 25 and 30 as the international classification (Lancet 2004;363(9403):157-163), and why Singapore's Health Promotion Board treats a BMI of 23 and above as outside the healthy range. Lean mass drives resting expenditure, so at a given weight a higher fat fraction means a slightly lower true BMR than a formula fitted to a leaner population will predict.
For scale, HealthHub puts the average Singaporean adult's daily energy need at about 2,200 kcal for men and 1,800 kcal for women — figures based on the average weight and activity of the population, not targets for any individual, which is exactly the gap a personal TDEE estimate is meant to close. Alongside calories, the Health Promotion Board asks adults to watch waist circumference — 90 cm and above for men, 80 cm and above for women, marks abdominal obesity in Asians — because central fat carries metabolic risk that neither BMI nor a calorie target shows. Shared dishes and unlabelled portions at hawker centres make intake harder to log than packaged food, which is one more reason to judge the target by weight change rather than by a food diary alone.
"This ubiquitous weight-loss rule (also known as the 3500 kcal per pound rule) was derived by estimation of the energy content of weight lost but it ignores dynamic physiological adaptations to altered body weight …"
Hall et al., The Lancet 2011The Protein Question: How Much Do Singaporeans and Malaysians Actually Need
The WHO/FAO/UNU expert consultation sets the safe protein intake for adults at 0.83 g per kilogram of body weight per day (WHO Technical Report Series 935, 2007), and the US Dietary Reference Intake is 0.8 g/kg/day (Institute of Medicine, 2005) — the figure this calculator uses for the Maintain goal. That is a floor against deficiency, not a target for changing body composition. For people trying to lose fat while keeping muscle, or to add muscle, Morton and colleagues' meta-analysis of 49 resistance-training trials found that protein intakes above about 1.6 g/kg/day produced no further gain in fat-free mass (Br J Sports Med 2018;52(6):376-384) — which is why the Lose and Gain goals here use 1.6 g/kg.
Hitting that target on hawker food is genuinely harder than on plated Western meals: rice- and noodle-based dishes deliver their protein alongside a large carbohydrate and oil load, and shared dishes make portions hard to weigh. Singapore's Health Promotion Board publishes per-dish energy and nutrient figures in its Energy & Nutrient Composition of Food database on HealthHub, which is the place to look a specific dish up rather than trusting a guess.
Practical high-protein options in the local food landscape include tofu and tempeh (yong tau foo stalls, and widely sold in Malaysia and Indonesia), steamed fish at economic-rice stalls, poached or roast chicken without skin, fish balls in noodle soups, and eggs at any kopitiam. Adding a side of tofu or an extra portion of lean protein to your usual hawker meal is usually the most practical way to close the gap without changing your food culture.
The macro targets here use 1.6 g/kg of protein for the Lose and Gain goals and 0.8 g/kg for Maintain; fat is set at 25% of goal calories — inside the 20–35% acceptable range the Institute of Medicine publishes — and carbohydrate takes the remainder. If the protein figure is hard to reach with local food, a whey or plant-based protein powder dissolved in water is a low-calorie top-up; it is a convenience, not a requirement.
Mifflin-St Jeor, and the 23 hours you are not exercising
The Mifflin-St Jeor equation (1990) was fitted to 498 healthy US adults; in that sample the 1919 Harris-Benedict equations overestimated measured resting expenditure by about 5%.
Even if you exercise 1 hour daily, you spend 23 hours not exercising — making your base metabolic rate far more important than exercise calories.
HealthHub puts the average Singaporean's daily need at about 2,200 kcal for men and 1,800 for women — population figures based on average weight and activity, not personal targets.
Skeletal muscle spends roughly 13 kcal per kg per day at rest against about 4.5 for fat tissue — Elia's 1992 figures, which Wang and colleagues found held up against MRI-measured organ masses in adults up to 50 (Am J Clin Nutr 2010;92(6):1369-1377). Lean mass is a real driver of your TDEE.
Metabolic adaptation is real: six years after "The Biggest Loser", contestants' resting expenditure was still about 500 kcal/day below what their body composition predicted (Fothergill et al., Obesity 2016;24(8):1612-1619).
The 3,500-kcal-per-pound rule (Wishnofsky 1958) overstates long-run loss: as weight falls, so does expenditure, and the deficit shrinks with it (Hall et al., Lancet 2011;378:826-837). Even the energy in a kilogram lost depends on how much body fat you start with (Hall, Int J Obes 2008;32(3):573-576).
FAO/WHO/UNU classify a sedentary lifestyle as a physical activity level of 1.40–1.69 and a vigorous one as 2.00–2.40 (Human Energy Requirements, 2004); the 1.2–1.9 ladder used here is a calculator convention, and its 1.2 is nearer the 1.21 FAO gives for people who are totally inactive.
NEAT — non-exercise activity thermogenesis, the energy of fidgeting, standing and walking about — can differ by up to 2,000 kcal/day between people of the same weight (Levine et al., Arterioscler Thromb Vasc Biol 2006;26(4):729-736).
Mifflin-St Jeor predicts resting expenditure only; the activity multiplier is meant to cover movement and digestion, which is why exercise calories must not be added on top of your TDEE.
Frankenfield's 2005 review found Mifflin-St Jeor within 10% of measured resting rate more often than Harris-Benedict, Owen or WHO/FAO/UNU — and still missed some individuals by more, which is why the result is a starting point.
Frequently Asked Questions
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TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a day, including exercise, digestion, and all daily activity. It matters because it is the definitive reference point for body composition: consistently eat below your TDEE to lose weight, at your TDEE to maintain, or above it to gain muscle mass. Without knowing your TDEE, any calorie target you follow is essentially a guess.
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It is the equation a 2005 systematic review (Frankenfield et al., J Am Diet Assoc 2005;105(5):775-789) found most reliable among those in common use, but the same review noted that ethnic minorities were under-represented in the studies that built and validated it, and Mifflin's own 1990 sample was US adults. Body-composition differences measured in Singaporeans (Deurenberg-Yap et al., 2000) mean a formula fitted to a leaner population can run slightly high here. Use the result as a starting estimate and adjust by 100–200 kcal after two to four weeks of real weight change.
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This calculator's "Lose Weight" goal subtracts 500 kcal/day from your TDEE. By the classic 3,500-kcal-per-pound rule (Wishnofsky 1958) that is about 0.45 kg a week; in practice the rate slows over time because expenditure falls as weight falls (Hall et al. 2011). The NHS suggests aiming to lose 0.5 to 1 kg a week. NICE's 2025 obesity guideline (NG246) reserves diets of 800 to 1,200 kcal a day for specialist weight-management services and diets under 800 kcal a day likewise, so if the target printed here is that low, the result flags it and you should talk to a doctor or dietitian first.
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There is no single figure. NICE asks only that a weight-loss diet keep intake below expenditure, with support and follow-up; the NHS suggests a pace of 0.5 to 1 kg a week. At 500 kcal/day the weekly deficit is 3,500 kcal — roughly 0.45 kg by Wishnofsky's 1958 rule, less as your expenditure adapts. What NICE does draw a line under is total intake: diets of 800 to 1,200 kcal a day belong within specialist services, as do diets under 800. A smaller deficit means slower progress; choose one you can keep, and judge it by your weight over several weeks.
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The WHO/FAO/UNU safe intake is 0.83 g per kg of body weight per day (Technical Report Series 935, 2007) and the US RDA is 0.8 g/kg (Institute of Medicine, 2005) — this calculator uses 0.8 for the Maintain goal. For fat loss with muscle retention, or for gaining muscle, Morton and colleagues' 2018 meta-analysis found no further gain in fat-free mass above about 1.6 g/kg/day, which is the figure used for the Lose and Gain goals. Good local sources include tofu, tempeh, fish, chicken, eggs and fish balls.
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Different calculators use different BMR formulas (Harris-Benedict, Mifflin-St Jeor, Katch-McArdle) and different activity multiplier scales. This calculator uses Mifflin-St Jeor with the common five-level activity scale. The equations themselves disagree: in Mifflin's own sample the 1919 Harris-Benedict equations overestimated measured resting expenditure by 5%, and the 2005 review found even Mifflin-St Jeor missing some individuals by more than 10%. Differences between calculators are smaller than that error. The most reliable approach is to pick one calculator, use it consistently, and adjust based on 2–4 weeks of real-world results.
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Yes. Mifflin-St Jeor takes only age, sex, height and weight, so it applies anywhere; what changes by population is the accuracy, as the caveats above explain. Both metric and imperial units are supported. Treat the result as a starting estimate — adjustment against real-world weight change over two to four weeks beats any formula.
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It depends on body weight, intensity and duration. By the MET method a 70 kg adult running 30 minutes at 10 km/h burns about 325 kcal (9.3 METs for running at 6–6.3 mph in the 2024 Adult Compendium of Physical Activities — see our Calories Burned Calculator). Crucially, exercise is already inside your TDEE through the activity multiplier, so do not add it on top; and a post-run snack can undo the session's deficit in a few mouthfuls.
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BMR (Basal Metabolic Rate) is the calories your body burns at complete rest to sustain basic life functions — breathing, circulation, and organ function. TDEE adds on top of BMR all the calories burned through physical activity, digestion (thermic effect of food), and incidental daily movement. This calculator multiplies BMR by 1.2 for its sedentary setting and up to 1.9 for the most active; FAO/WHO/UNU measure a sedentary lifestyle at 1.40–1.69 times BMR and a vigorous one at 2.00–2.40. You should always base your calorie targets on TDEE, not BMR — eating at BMR level would leave most people in a large deficit.
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Method & sources
How it computes
EnergyNeedsKernel: Mifflin-St Jeor 1990 resting energy (10 × kg + 6.25 × cm − 5 × age + 5 for men, −161 for women) × an activity factor of 1.2, 1.375, 1.55, 1.725 or 1.9, a calculator convention (FAO/WHO/UNU PAL bands run 1.40-2.40). Goal = TDEE − 500, TDEE or TDEE + 300. Macros: protein 0.8 g/kg to maintain or 1.6 g/kg, fat 25% of kcal, carbohydrate the rest. A loss target under NICE NG246's 1,200 or 800 kcal/day line is flagged.
What this tool implements
- Mifflin-St Jeor 1990 simplified sex-specific equations exactly as published (10 / 6.25 / 5 / +5 / −161)
- Activity multipliers 1.2–1.9 are the common calculator convention, not part of Mifflin's paper; FAO/WHO/UNU PAL categories (sedentary 1.40–1.69, active 1.70–1.99, vigorous 2.00–2.40; Human Energy Requirements, 2004) are cited on the page for scale
- Protein: 0.8 g/kg (US RDA, Institute of Medicine 2005; the WHO/FAO/UNU 2007 safe intake is 0.83 g/kg) for maintain, 1.6 g/kg for lose/gain per the Morton et al. 2018 breakpoint; fat 25% of kcal, inside the IOM 20–35% acceptable range
- 500 kcal/day deficit ≈ 0.45 kg/week by the Wishnofsky (1958) 3,500 kcal/lb rule, presented as a rule of thumb whose rate slows as expenditure falls (Hall et al., Lancet 2011)
- FAO/WHO/UNU 2004, Table 5.3 and §5: the report gives 1.21 for people who are totally inactive and dependent, so the calculator's 1.2 "Sedentary" sits below FAO's sedentary band; the page says so. The same report puts BMR at 45-70% of total expenditure and the thermic effect of food at about 10% of BMR.
- NICE NG246 (2025) 1.16.8-1.16.9: low-energy diets of 800-1,200 kcal/day and very-low-energy diets under 800 only within specialist services. A loss target under either line is flagged on the result, not hidden; NHS guidance of 0.5-1 kg a week is quoted for pace.
Sources
- 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. https://doi.org/10.1093/ajcn/51.2.241
- Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc 2005;105(5):775-789. https://doi.org/10.1016/j.jada.2005.02.005
- Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med 2018;52(6):376-384. https://doi.org/10.1136/bjsports-2017-097608
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press; 2005. https://doi.org/10.17226/10490
- FAO/WHO/UNU. Human Energy Requirements: Report of a Joint FAO/WHO/UNU Expert Consultation, Rome, 17-24 October 2001. FAO Food and Nutrition Technical Report Series 1; 2004. Table 5.3: https://www.fao.org/4/y5686e/y5686e07.htm
- National Institute for Health and Care Excellence. Overweight and obesity management (NG246), 2025, recommendations 1.16.8-1.16.9. https://www.nice.org.uk/guidance/ng246/chapter/Physical-activity-…
- Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet 2011;378(9793):826-837. https://pmc.ncbi.nlm.nih.gov/articles/PMC3880593/
- Hall KD. What is the required energy deficit per unit weight loss? Int J Obes 2008;32(3):573-576. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/
What can make this go out of date
- None at runtime — the equation coefficients and reference intakes are fixed publications; HealthHub's population calorie figures (2,200 kcal men / 1,800 kcal women) quoted in the prose are HPB's and may be revised.
Abridged — the full review record for this tool runs longer than the list above.
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