Calories from steps: how we count them

1 The short version

Four facts that everything else follows from. Numbers in square brackets link to the sources at the end of the article.

• The app counts the net calories of walking - only the energy your body spent above its resting metabolism. Apple defines «active energy» the same way [1], but for Apple it is all of the day's activity, and for us it is only steps.
• The coefficient of 0.30 kcal per pound of body weight per mile (the same thing: 1.72 joules per kilogram per metre) sits inside the range measured in laboratories with gas analysis: from 1.64 J/kg/m at the most economical speed [4] to 2.22 J/kg/m for an average adult [5].
• A watch estimates too, it does not measure. In a test of seven wrist devices not one had a calorie error below 20% [8]; when walking, the Apple Watch Series 6 overestimated by 20% on average [9]; the conclusion of a systematic review of 158 studies: for energy expenditure no brand was accurate [11].
• So our «calories from steps» cannot be compared directly with Apple's ring: these are different quantities, obtained by different methods, each with its own margin of error. With the «calories» in Google Fit and Google Health even less so: by Google's own documentation those include resting metabolism as well [14, 15].

2 How the app counts calories from steps

The formula is the same on iPhone and Android. It needs three numbers from your profile - height, weight, sex - and the number of steps for the day. The example below: a man, 75 kg, 175 cm, 10,000 steps.

1. Step length. Height × 0.415 for men or height × 0.413 for women.
   175 cm × 0.415 = 72.6 cm.
2. Distance covered. Steps × step length.
   10,000 × 72.6 cm = 7.26 km.
3. Energy spent per mile. 0.30 kcal × body weight in pounds (kilograms × 2.2).
   75 kg = 165 lb, 0.30 × 165 = 49.5 kcal per mile (1,609 m).
4. Steps in a mile. 160,934.4 cm ÷ step length.
   160,934.4 ÷ 72.6 = 2,216 steps.
5. Calories per step and the total. Energy per mile ÷ steps per mile, multiplied by steps.
   49.5 ÷ 2,216 = 0.0223 kcal per step; 10,000 steps = 223 kcal.

Step length from height is an averaged rule that pedometers use: a real person's stride changes with speed. So both the distance and the calories here are a calculation from averages, not a measurement. Nobody gives you an exact figure without a gas analyser - neither the app nor a watch.

3 Why we count only the energy above rest

Your daily norm in the app is calculated with the Mifflin-St Jeor equation and already includes resting metabolism for all 24 hours. If the full cost of walking, resting metabolism included, were added on top of the norm, the minutes spent on your feet would be counted twice. Until July 2026 the app used a coefficient of 0.57 - that is the cost including resting metabolism, which is why for heavier users the «Steps» line exceeded even a fully closed Move ring. It was replaced with the net coefficient of 0.30.

For the same reason the activity level in your profile is chosen by your workouts («fitness 3 times a week», «heavy physical work»), not by your walking: walking reaches the diary as steps, on its own line. Raise the activity level «because I walk a lot» and your walking gets counted twice.

4 What Apple shows: Fitness and Health

In the Health app, Apple describes active energy as an estimate of the energy your body uses during the day in an active state, above resting energy - for any physical activity: slow walking, housework, cycling, dancing. The developer documentation says the same: active energy is the energy burned due to physical activity and exercise, excluding resting energy [1].

How it is worked out depends on the device:

• An Apple Watch uses heart rate, the accelerometer, and your height, weight, sex and age from the Health profile, plus the calibration the watch builds up on GPS walks [2]. The formula is not published.
• An iPhone without a watch estimates active calories from its motion sensors: steps, distance and flights climbed [3]. Exactly how, Apple does not disclose either.

So the Move ring for the day is walking plus everything else: standing, housework, workouts, arm movement. Our «Steps» line is walking only. Even with the same step count the ring will be higher, and that is correct.

5 What Google Fit, Google Health and other Android apps show

On Android the word «calories» covers two different quantities, depending on the app.

• Google Fit (being replaced by Google Health during 2026): its «Calories» figure is the total expenditure for the day, including calories burned at rest - that is what Google's documentation says [14]. Google Health, the former Fitbit app, works the same way: «calories burned» combine basal metabolic rate with activity, and the number grows even while you sleep [15]. Most of such a figure is simply your body doing its job at rest.
• Health Connect, through which Android apps exchange data, separates «active calories» - without basal metabolism - from «total calories», which include it [13]. Only the first is worth comparing with the «Steps» line, and only bearing in mind that it covers the whole day's activity.
• Samsung Health, Huawei Health, Mi Fitness and watch companion apps use their own closed algorithms and each decides for itself whether to show resting metabolism. What exactly their figure means is written in their own help.

Hence the difference in complaints: an Apple user sees a figure one and a half to two times larger than ours, a Google Fit user several times larger. In the second case things that cannot be compared at all are being compared: the body's daily expenditure against the energy of walking alone.

6 Three reasons the numbers do not match

1. Different quantities

Apple's ring: all of the day's activity. The «Steps» line: the energy of walking. A workout that a person logged separately is already inside Apple's ring, while with us it sits on its own line.

2. Different margins of error, on both sides

Our calculation is a formula for an average person: it does not know whether you walked uphill or on the flat, quickly or slowly, walked or ran (running steps are priced as walking, that is, on the low side). A watch's estimate is a model built on heart rate and movement, and in laboratory tests it is off by 20-40%, more often on the high side (see the table below). Two approximate numbers are under no obligation to agree.

3. Different input data

Our figure depends on just three numbers in the app's profile: height, weight, sex. The watch's figure depends on the Health profile, heart rate, calibration and a model Apple does not publish. Making the weight identical in both profiles will not make the numbers equal - the methods still differ. But an out-of-date weight in our profile makes our figure wrong on its own terms: 10 kg at a body weight of 75 kg is about 13%.

7 How accurate the watches themselves are

Laboratory tests against a gas analyser - the only way to measure energy expenditure rather than estimate it.

8 Where our coefficient sits among laboratory measurements

To compare different methods, let us put them all in one unit: joules per kilogram of body weight per metre travelled. Our coefficient of 0.30 kcal/lb/mile equals 1.72 J/kg/m.

1234567

The cost of walking, J/kg/m. The orange band holds the laboratories' net values, the grey one gross values, resting metabolism included

1. 11.64 - Minetti et al., 2002: the minimum cost of walking at the most economical speed, around 1.0 m/s; 10 runners on a treadmill [4]
2. 21.72 - our coefficient of 0.30 kcal per pound per mile, the orange dot
3. 32.09 - the ACSM equation: horizontal component 0.1 ml O₂ per kg per metre, 5 kcal per litre of O₂, net [6]
4. 42.22 - Tucker et al., 2024: 205 adults aged 18-81, treadmill at 4.8 km/h, net of standing [5]
5. 52.34 - Compendium 2024: walking at 2.8-3.4 mph, 3.8 MET, converted for 5 km/h, net (minus 1 MET) [7]
6. 63.18 - Compendium 2024, gross: the same figure with resting metabolism included
7. 73.27 - the old coefficient of 0.57, used until July 2026, gross

The same example (75 kg, 175 cm, 10,000 steps, 7.26 km) by each method:

The spread between honest laboratory methods is 214 to 305 kcal for one and the same walk, that is, more than 40%. There is no «correct» number inside that spread: without a gas analyser nobody knows it, neither an app nor a watch. Our figure sits in the lower, cautious part of the range: for someone watching their weight it is better to under-count the calories they have «earned» than to over-count them.

9 Which figure to trust in your diary

Ours. Not because it is more accurate than a watch - there is no accurate figure here for anyone - but because it is calculated within the same system as everything else in the diary. The daily norm from Mifflin-St Jeor already contains resting metabolism, so only energy above rest and only for walking is added to it - and that is the «Steps» line. Put the Move ring or a Google Health figure there instead, and rest and the rest of your activity enter the balance a second time, making the deficit on screen larger than it really is.

Let the ring be the ring: it was built for its own job - closing it by the evening - and it does that job well. Two figures about different things are under no obligation to agree, and there is nothing you need to do about it.

10 Units used in this article

11 Sources

1. Apple Developer Documentation. HKQuantityTypeIdentifier.activeEnergyBurned - the definition of active energy: energy from physical activity, excluding resting energy. developer.apple.com
2. Apple Support. Calibrate your Apple Watch for improved Workout and Activity accuracy - the watch uses height, weight, gender, age and calibration to work out calories. support.apple.com/en-us/105048
3. Apple Support. Get started with Fitness on iPhone - an iPhone without a watch estimates active calories from its motion sensors. support.apple.com
4. Minetti A.E., Moia C., Roi G.S., Susta D., Ferretti G. Energy cost of walking and running at extreme uphill and downhill slopes. Journal of Applied Physiology, 2002; 93: 1039-1046. doi.org/10.1152/japplphysiol.01177.2001
5. Tucker et al. Treadmill walking economy is not affected by body fat and body mass index in adults. Physiological Reports, 2024. pmc.ncbi.nlm.nih.gov/articles/PMC11101323
6. ACSM Metabolic Calculations (walking and running equations) - VO₂ = 0.1 × speed + 1.8 × speed × grade + 3.5 ml/kg/min. depts.ttu.edu (PDF)
7. 2024 Adult Compendium of Physical Activities. Walking - codes 17170, 17190, 17200: 2.5 mph - 3.0 MET; 2.8-3.4 mph - 3.8 MET; 3.5-3.9 mph - 4.8 MET. pacompendium.com/walking
8. Shcherbina A. et al. Accuracy in wrist-worn, sensor-based measurements of heart rate and energy expenditure in a diverse cohort. Journal of Personalized Medicine, 2017; 7(2): 3. doi.org/10.3390/jpm7020003
9. Le et al. Validity of three smartwatches in estimating energy expenditure during outdoor walking and running. Frontiers in Physiology, 2022. pmc.ncbi.nlm.nih.gov/articles/PMC9549133
10. Falter M. et al. Accuracy of Apple Watch measurements for heart rate and energy expenditure in patients with cardiovascular disease. JMIR mHealth and uHealth, 2019. doi.org/10.2196/11889
11. Fuller D. et al. Reliability and validity of commercially available wearable devices for measuring steps, energy expenditure, and heart rate: systematic review. JMIR mHealth and uHealth, 2020; 8(9): e18694. mhealth.jmir.org/2020/9/e18694
12. Kostrna J. et al. Body fat, skin tone, and the accuracy of smartwatch caloric expenditure estimates. PLoS One, 2026. doi.org/10.1371/journal.pone.0353261
13. Google Health API. Calories and energy data types - «Active calories» exclude basal metabolism, «Total calories» include it. developers.google.com/health/data-types/calories
14. Google Fit. Activity data types, com.google.calories.expended - total calories burned, including calories burned at rest (BMR). developers.google.com/fit/datatypes/activity
15. Google Health Help. How does my Fitbit device calculate my daily activity? - «calories burned» combine basal metabolic rate with activity data; BMR is based on height, weight, sex and age from the profile. support.google.com/googlehealth/answer/14237111