Daily calorie & macro calculator

The short version

Your daily calories are your resting energy times how active your day is, adjusted for your goal. Protein is set from your weight, fat is a fixed share of calories, carbohydrate is whatever is left, and fibre is a fixed amount. Each of those steps comes from a published guideline:

The rest of this page goes through each step, with the equations and the reasoning, so you can check any number Bud gives you.

Step 1How much energy you use at rest

Your basal metabolic rate (BMR) is the energy your body uses just to keep running - breathing, circulation, keeping warm. It is most of what you burn in a day. The international standard for predicting it is the set of equations in the FAO/WHO/UNU expert report on human energy requirements³, which work from your weight, age and sex:

Weight is in kilograms. An age of exactly 30 or 60 uses the older band.

Then comes the Indian adjustment. When ICMR's National Institute of Nutrition (ICMR-NIN) reviewed its Nutrient Requirements for Indians in 2020, it found that these international equations overestimate the BMR of Indian adults by 10–12%. The data behind them came largely from young, muscular subjects, and Indians carry relatively more body fat at the same weight¹. ICMR's method lowers the result by about 10%. Applied as 10% for men and 9% for women, it reproduces ICMR's own published requirements to the calorie, so that is exactly what Bud does:

Step 2How active you are

Your day's total is your resting energy multiplied by a physical activity level (PAL). ICMR-NIN recalculated these for India using the measured energy cost of activities in Indian studies, which came out lower than the Western figures: a sedentary day is 1.4, where it was 1.53 in ICMR's 2010 guidance¹.

Two of the four levels are ICMR's own figures and two are worked out between them. Most people who use Bud sit at a desk, and how often they work out is what separates them. The FAO/WHO/UNU report puts a sitting day with a little activity anywhere from 1.40 to 1.69, and notes that an hour of moderate to vigorous exercise a day raises a person's PAL by about 0.2, "from 1.55 to 1.75"³. So "lightly active" is 1.5 and "moderately active" is ICMR's 1.4 plus that 0.2, both inside that band; and "very active" - working out regularly - is 1.8, ICMR's moderate work and inside FAO/WHO/UNU's active band of 1.70–1.99. ICMR's heavy-work figure, 2.3, is a labourer's day, and Bud doesn't use it: on a desk job with regular workouts it would put your calories about 30% too high.

Step 3Your goal

The figure from step 2 is what keeps your weight where it is. Your goal then moves it:

Weight loss. The 2013 AHA/ACC/TOS obesity guideline - one of its strongest recommendations - prescribes a deficit of 500 or 750 kcal a day, or a fixed intake of 1,200–1,500 kcal for women and 1,500–1,800 for men⁶. Bud uses the smaller deficit, because a pace you can keep for months beats a fast first fortnight, and never sets a target below the bottom of those ranges: 1,200 kcal for women and 1,500 for men.

Diabetes care. For somebody with type 2 diabetes who is overweight, losing 5% or more of their weight is a first-line recommendation of the American Diabetes Association's Standards of Care¹¹. At a healthy weight there is nothing to lose, so the target is maintenance.

GLP-1 medication. These drugs suppress appetite so effectively that the usual problem is eating too little and losing muscle along with fat. The 2025 joint advisory from four obesity and nutrition societies warns that intakes below 1,200 kcal a day for women or 1,800 for men risk falling short on vitamins and minerals⁷, so those are the floors.

Muscle building. A review of nutrition for natural lifters recommends a surplus of about 10–20% over maintenance¹⁰. Bud uses the lower end, because a bigger surplus adds fat faster rather than muscle.

Nobody with a BMI under 18.5, and nobody under 18, is given a deficit, whatever goal they pick. If you pick several goals, your calories follow one of them - GLP-1 first, then weight loss, diabetes care and muscle building - and protein takes the highest figure among the goals you picked.

Step 4Protein

ICMR-NIN's recommended allowance for Indian adults is 0.83 g of protein per kg of body weight. For people whose diet is mostly cereal, with lower-quality protein, it is 1 g per kg¹ - which describes most Indian plates, so that is Bud's figure for general nutrition. While you're losing weight, more protein helps you lose fat rather than muscle, and 1.2–1.6 g per kg is the range the 2025 GLP-1 advisory cites for that⁷. For building muscle, the International Society of Sports Nutrition recommends 1.4–2.0 g per kg⁸, and a meta-analysis of 49 trials found no extra gain beyond about 1.6⁹.

Protein is worked out on a healthy weight. Muscle, not body fat, is what sets how much protein you need, so working it out on your total weight overstates it for anyone carrying extra fat - a point the GLP-1 advisory makes directly⁷. Bud uses your weight or the top of the healthy range for your height (a BMI of 24.9), whichever is lower.

Step 5Fat, carbohydrate and fibre

Fat is 25% of your calories. WHO's 2023 guideline recommends that adults get 30% of their energy from fat or less, mostly from unsaturated fats, with saturated fat under 10%⁵. ICMR-NIN's 2024 Dietary Guidelines for Indians set the same 30% ceiling². A quarter sits comfortably inside it.

Carbohydrate is what is left once protein (4 kcal a gram) and fat (9 kcal a gram) are taken out of your calories. Protein and fat are set first because a deficit should never squeeze out protein. WHO's 2023 carbohydrate guideline puts the emphasis on where carbohydrate comes from: whole grains, vegetables, fruit and pulses⁴. ICMR-NIN's guidelines add that cereals should provide no more than 45% of your energy, with half of them whole grains, and that added sugar should stay under 5%².

Fibre is 25 g a day, WHO's recommended minimum of naturally occurring fibre for adults⁴. It is part of your carbohydrate rather than counted on top of it.

A worked example

A 32-year-old woman, 160 cm and 70 kg, who sits at a desk most of the day and wants to lose weight:

1. Resting energy: 8.126 × 70 + 845.6 = 1,414 kcal, less 9% = 1,287 kcal.
2. Mostly sitting: 1,287 × 1.4 = 1,802 kcal to stay at 70 kg.
3. Weight loss: 1,802 − 500 = 1,302, rounded to 1,300 kcal.
4. Protein: the top of her healthy range is 24.9 × 1.6² = 63.7 kg, below her weight, so 1.2 × 63.7 = 76 g.
5. Fat: 1,300 × 0.25 ÷ 9 = 36 g. Carbs: (1,300 − 304 − 324) ÷ 4 = 168 g. Fibre: 25 g.

Her BMI is 27.3, which WHO classes as overweight; the healthy range for her height is 47–64 kg. Put the same details in the calculator above and you'll get the same five numbers.

What these numbers can't do

• They're a starting point. Any equation predicts the average for people like you, and an individual can be 10% either side. If your weight hasn't moved the way you expected after three or four weeks of honest logging, the target needs adjusting - tell Bud, or your dietitian.
• They're for healthy adults. Pregnancy, breastfeeding, kidney disease, a history of disordered eating and many medications change what you need. Follow your doctor's or dietitian's advice over any calculator.
• A dietitian's numbers come first. If you work with a dietitian through Bud and they set your targets, Bud uses theirs, not these.

Common questions

References

1. ICMR–National Institute of Nutrition. Nutrient Requirements for Indians: Recommended Dietary Allowances and Estimated Average Requirements. Report of the Expert Group, 2020. nin.res.in/rdabook/brief_note.pdfEnergy as BMR × PAL; BMR 10% below FAO/WHO/UNU for adults; sedentary PAL 1.4; reference requirements; protein 0.83 g/kg (1 g/kg on cereal-based diets).
2. ICMR–National Institute of Nutrition. Dietary Guidelines for Indians. Hyderabad, 2024. nin.res.in/dietaryguidelinesTotal fat at or below 30% of energy; cereals at most 45% of energy, half whole grain; added sugar under 5%.
3. FAO/WHO/UNU. Human energy requirements: report of a Joint FAO/WHO/UNU Expert Consultation. Food and Nutrition Technical Report Series 1. Rome, 2004. fao.org/4/y5686eBMR equations (Table 5.2); lifestyle bands of 1.40–1.69 (sedentary or light) and 1.70–1.99 (active); an hour of daily exercise raises PAL by about 0.2.
4. World Health Organization. Carbohydrate intake for adults and children: WHO guideline. Geneva, 2023. who.int/publications/i/item/9789240073593At least 25 g of naturally occurring dietary fibre a day for adults; carbohydrate mainly from whole grains, vegetables, fruit and pulses.
5. World Health Organization. Total fat intake for the prevention of unhealthy weight gain in adults and children: WHO guideline. Geneva, 2023. who.int/publications/i/item/9789240073654Total fat at 30% of energy or less for adults.
6. Jensen MD, Ryan DH, Apovian CM, et al. 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults. Circulation. 2014;129(25 Suppl 2):S102–S138. doi.org/10.1161/01.cir.0000437739.71477.eeA 500 or 750 kcal/day deficit, or 1,200–1,500 kcal (women) and 1,500–1,800 kcal (men).
7. Mozaffarian D, Agarwal M, Aggarwal M, et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity. 2025;33(8):1475–1503. doi.org/10.1002/oby.24336Protein 1.2–1.6 g/kg during weight loss; actual weight can overestimate protein needs; micronutrient risk below 1,200 kcal (women) and 1,800 kcal (men).
8. Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. doi.org/10.1186/s12970-017-0177-81.4–2.0 g/kg a day for exercising adults building or keeping muscle.
9. 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. doi.org/10.1136/bjsports-2017-097608No further gain in lean mass beyond about 1.62 g/kg a day.
10. Iraki J, Fitschen P, Espinar S, Helms E. Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review. Sports. 2019;7(7):154. doi.org/10.3390/sports7070154An energy surplus of about 10–20% for gaining muscle.
11. American Diabetes Association Professional Practice Committee. 8. Obesity and Weight Management for the Prevention and Treatment of Type 2 Diabetes: Standards of Care in Diabetes—2025. Diabetes Care. 2025;48(Suppl 1):S167. doi.org/10.2337/dc25-S008Weight loss of 5% or more for people with type 2 diabetes and overweight or obesity.
12. World Health Organization. Body mass index (BMI). Global Health Observatory. who.int/data/ghoBMI categories used for the healthy weight range.