Calorie deficit calculator: factor in your steps for the day

A calorie deficit is the gap between what you burn and what you eat. To estimate it, this tool starts from your basal metabolic rate and your actual number of steps. Example: a 30-year-old woman, 1.65 m, 65 kg, who takes 8,000 steps a day burns about 1,870 kcal per day.

Estimated expenditure: about 1,910 kcal per day

Basal metabolic rate (Mifflin-St Jeor): 1,400 kcal

Daily base (basal metabolic rate × 1.2): 1,680 kcal

Of which walking (8,000 steps): about 230 kcal extra

Estimate based on population formulas, with a real margin of error. Your actual expenditure is often higher than this result. The absence of an alert does not mean this deficit is risk-free. This is neither medical advice nor a goal. Pregnancy, breastfeeding, eating disorders, illness, under 18: talk to a doctor or a dietitian first.

This tool does not set you any goal. It estimates what you burn then, if you enter a deficit you are considering, it tells you which intake that corresponds to and warns you when it falls below a caution mark. It calculates no deficit if your BMI is under 18.5. The absence of a warning does not mean a deficit is risk-free.

How the basal metabolic rate is calculated

Basal metabolic rate (what your body burns at rest), Mifflin-St Jeor equation (Mifflin et al., American Journal of Clinical Nutrition, 1990, 498 adults aged 19 to 78, measured by indirect calorimetry):

man: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
woman: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Example (woman, 65 kg, 165 cm, 30 years old): 650 + 1,031.25 − 150 − 161 = 1,370 kcal.

How the rest of the expenditure is calculated

Daily base = basal metabolic rate × 1.2. It covers rest, digestion and everyday movements other than walking. The 1.2 is a choice made by the tool, not a measurement: we kept it low so as not to count walking twice, since it is added separately. Example: 1,370 × 1.2 = 1,640 kcal. This choice gives a rather low result: from 1.24 to 1.45 times the basal metabolic rate in our table, whereas the FAO places a sedentary or light lifestyle between 1.40 and 1.69 (Human Energy Requirements, 2004, table 5.3). Your real expenditure is often higher.
Net cost of walking (above rest), Ludlow and Weyand equation (Journal of Applied Physiology, 2016): net oxygen consumption = 3.85 + 5.97 × V² ÷ height (V in metres per second, height in metres), in ml of oxygen per kg per minute. It is converted to kcal with about 5 kcal per litre of oxygen (convention of the tool). The speed comes from the cadence (80, 100 or 120 steps per minute, values chosen by the tool, 100 being the threshold of moderate walking) and from the step length (height × 0.413 for a woman, × 0.415 for a man, approximation by Hatano, 1993). Example: 8,000 steps at 100 steps per minute = 80 minutes. At 1.65 m, V ≈ 1.13 m/s, which is about 0.0426 kcal per kg per minute: 80 × 0.0426 × 65 ≈ 220 kcal.
Total expenditure = daily base + walking: 1,640 + 220 ≈ 1,870 kcal (results are rounded to 10 kcal).
Intake matching a deficit = expenditure − deficit. Calculation example only: 2,000 kcal of expenditure − 300 kcal = 1,700 kcal. This is not advice.

Table: what steps change

Estimated total expenditure per day, at 100 steps per minute (rounded to 10 kcal).

Profile	2,000 steps	5,000 steps	8,000 steps	10,000 steps	12,000 steps
Woman, 30 years old, 1.65 m, 65 kg	1,700	1,780	1,870	1,920	1,980
Man, 35 years old, 1.80 m, 80 kg	2,180	2,290	2,390	2,470	2,540

Going from 5,000 to 10,000 steps adds about 140 kcal (woman) or 180 kcal (man) per day in this calculation. Walking weighs less than the basal metabolic rate: it makes up most of the expenditure.

Caution marks: when the tool warns you

The tool calculates the BMI (weight ÷ height², WHO: thinness under 18.5) and reacts in five cases:

BMI under 18.5 and a deficit being considered: no intake is calculated. The tool refers you to a doctor or a dietitian.
BMI from 18.5 to 25 and a deficit being considered: it reminds you that ANSES points out the risks of trying to lose weight without a medical indication.
BMI outside 12 to 70: it treats it as an entry error.
Intake under 1,200 kcal per day (woman) or 1,500 kcal (man), a caution mark chosen by this tool (it is not an official recommendation). The comparison is made on the figure rounded to 10 kcal, as you see it. These are the bounds of the brackets used in the ANSES report on weight-loss practices (November 2010), which sorts diets into under 800, 800 to 1,200, 1,200 to 1,500 and over 1,500 kcal. ANSES does not set these figures as recommended minimums: it is our choice. The same report gives as a reference intake for usual physical activity 1,800 kcal (woman) and 2,200 kcal (man).
Intake under your estimated basal metabolic rate.

If a warning appears, talk to a doctor or a dietitian before going further. The absence of a warning does not mean the deficit is risk-free. ANSES writes that « dieting for weight loss is not a trivial act » and that « seeking weight loss without a formal medical indication carries risks ». It notes that these practices are often applied without medical justification (no overweight or obesity) and without medical follow-up.

This tool is not designed for: people under 18, pregnancy and breastfeeding, people who have or have had an eating disorder, chronic illnesses or treatments that change weight. For these situations, ask a health professional. No deficit is recommended to you here.

NEAT: steps are part of the « invisible » expenditure

NEAT (non-exercise activity thermogenesis) is the energy spent outside of sport: walking, standing, moving around. In a study by Levine and colleagues (Science, 2005), 10 lean people and 10 people with mild obesity, all sedentary, were followed for 10 days: the people with mild obesity spent on average 2 more hours a day sitting. The authors estimate that adopting the habits of the lean people could represent about 350 more kcal per day. It is a small sample and an estimate, not a promise. Steps are the part of NEAT that your phone can measure, which is why this tool takes them as input.

Limits

The formulas describe a population average. Two people who are identical on paper can have expenditures that differ by several hundred kcal.
The 1.2 coefficient counts neither your sport, nor a physical job, nor muscle mass. It can underestimate your expenditure.
The Mifflin-St Jeor formula comes from a study of 19 to 78 year olds: the tool is not designed for other ages.
Your phone's step counter is a little off depending on where you carry it.
Expenditure adapts when you eat less: a calculation made today does not hold in six months.
The result is an estimate to be rounded, not a figure to follow to the letter.

Frequently asked questions

How do you calculate your calorie deficit?

Estimate what you burn (basal metabolic rate + walking), then subtract the deficit you are considering: expenditure − deficit = intake. The tool does this and warns you if it falls below a caution mark. The deficit to aim for is not something to choose alone if you have any doubt: a health professional can help you.

How many calories to lose 1 kg?

There is no fixed figure. The rule often quoted, about 7,700 kcal per kg lost, is the conversion of Wishnofsky's 3,500 kcal per pound (1958). It overestimates the loss. In the CALERIE study, reported by Thomas et al. (J Acad Nutr Diet, 2014), one kg lost corresponded to about 4,860 kcal at 4 weeks and 6,570 kcal at 24 weeks.

Hall et al. (The Lancet, 2011) estimate with a model that, for an average overweight adult, a lasting change of 100 kJ (about 24 kcal) per day leads in the end to a difference of about 1 kg, half of it in about a year and 95% in about three years. These figures are averages, not a promise. The tool predicts no loss.

Is the calorie deficit different for a woman?

The formula changes: the constant is −161 for a woman and +5 for a man, which gives a lower basal metabolic rate at equal age, height and weight. The tool's caution mark changes too (1,200 versus 1,500 kcal). For pregnancy and breastfeeding, the tool is not suitable.

What is the difference between basal metabolic rate and calorie expenditure?

The basal metabolic rate is what your body burns at rest. Total calorie expenditure adds digestion, everyday movements, walking and sport.

Are my steps enough to create a deficit?

They raise your expenditure: from 5,000 to 10,000 steps, about 140 to 180 kcal more per day in this tool. What that does to your weight also depends on what you eat and on your body; the tool does not predict it.

Tracking your steps day to day

This calculation is only as accurate as your step count. To find it, see how to count your steps on iPhone, our selection of walking apps or the steps to km converter. StepsLink reads your steps from Apple Health and lets you follow them day after day.

Discover StepsLink on the App Store

Sources

Consulted on November 5, 2026 (abstracts for Mifflin, Ludlow and Levine; full text for the ANSES report, Thomas, Hall and the FAO).

Mifflin M.D., St Jeor S.T., Hill L.A., Scott B.J., Daugherty S.A., Koh Y.O., « A new predictive equation for resting energy expenditure in healthy individuals », Am J Clin Nutr, 1990, 51(2):241-247. PMID 2305711.
Ludlow L.W., Weyand P.G., « Energy expenditure during level human walking: seeking a simple and accurate predictive solution », J Appl Physiol, 2016, 120:481-494. PMID 26679617.
Levine J.A. et al., « Interindividual variation in posture allocation: possible role in human obesity », Science, 2005, 307:584-586. PMID 15681386.
Thomas D.M., Gonzalez M.C., Pereira A.Z., Redman L.M., Heymsfield S.B., « Time to correctly predict the amount of weight loss with dieting », J Acad Nutr Diet, 2014, 114(6):857-861 (PMC4035446): values from the CALERIE study; Wishnofsky's rule (Am J Clin Nutr, 1958) quoted from Thomas et al.
Hall K.D. et al., « Quantification of the effect of energy imbalance on bodyweight », The Lancet, 2011, 378:826-837. DOI 10.1016/S0140-6736(11)60812-X.
ANSES, « Évaluation des risques liés aux pratiques alimentaires d'amaigrissement » (risk assessment of weight-loss eating practices), collective expert report, November 2010. anses.fr
FAO/WHO/UNU, Human Energy Requirements, Food and Nutrition Technical Report Series 1, Rome, 2004, table 5.3 (activity levels: sedentary or light lifestyle = 1.40 to 1.69). fao.org
Tudor-Locke C. et al., « Walking cadence (steps/min) and intensity in 21-40 year olds: CADENCE-adults », Int J Behav Nutr Phys Act, 2019, 16:8 (threshold of 100 steps per minute).
Hatano Y., ICHPER Journal, 29(4), 1993, p. 4-8: step length coefficients, quoted from secondary sources (not consulted directly).

Updated November 5, 2026. The StepsLink team.