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Fat Loss Formula

Food-to-Exercise Conversion Formula

Food-to-exercise conversion expresses food calories as activity time at a given MET. 1 MET = 1 kcal/kg/hour. A 75 kg person walking at 3.5 MET burns ~262 kcal/hour. Useful for reframing portion sizes; not a literal calorie-canceling guide because EPOC + appetite compensation alter real-world totals.

4 VARIABLESPublished May 14, 2026Live Content
By AI Fit Hub · AI Fit Hub Team
Best Next MoveNutrition

Food-to-Exercise Converter

See how long you need to exercise to burn off any food, personalized by bodyweight.

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On This Page

Formula 4 variables Worked example Variations

Education · Not medical advice. Output is deterministic math from your inputs.Editorial standardsSponsor disclosureCorrections

Formula

Copy the exact expression or work through it step by step below.

minutes_to_burn = food_kcal / (MET × mass_kg × 0.0175) 0.0175 = (1 kcal/kg/hr) / (60 min/hr) Common MET values (Ainsworth Compendium 2011): Walking moderate (5 km/h): 3.5 Walking brisk (6.5 km/h): 4.5 Jogging: 7.0 Running 10 km/h: 9.8 Cycling moderate (15-20 km/h): 7.5 Cycling vigorous (25+ km/h): 12 Swimming freestyle moderate: 8.3 Lifting weights moderate: 5.0

Variables

minutes_to_burn

Minutes of activity to burn food kcal

Output in minutes. The longer the activity, the more EPOC + appetite compensation muddy the answer — treat as theoretical not literal.

food_kcal

Food energy

Calorie count of the food. From a nutrition label or food database (USDA FoodData Central, MyFitnessPal). Be honest — most home portions are 20-40% larger than labeled.

MET

Metabolic Equivalent of Task

Activity intensity multiplier. 1 MET = resting energy expenditure ≈ 3.5 ml O2/kg/min. Walking is 3.5 MET (3.5× resting). MET values from Ainsworth Compendium are population averages with ±15% individual spread.

mass_kg

Body mass

Body weight in kilograms. Heavier people burn more calories per minute at the same MET because more tissue to move.

Step By Step

  1. 1

    Look up MET value for your chosen activity in the Ainsworth Compendium.

    Cycling moderate (16-19 km/h on flat) = 7.5 MET.

  2. 2

    Find food kcal from label or database.

    Slice of pizza = 285 kcal.

  3. 3

    Apply formula.

    minutes = 285 / (7.5 × 75 × 0.0175) = 285 / 9.84 = 29 minutes.

  4. 4

    Adjust for personal MET reality. Untrained: subtract 5-10% (less efficient). Trained: subtract 10-15% (more economical, lower MET at same pace).

    Untrained cyclist: 29 × 0.95 = 28 min effective. Trained: 29 × 0.88 = 25 min.

  5. 5

    Don't take the number literally as 'canceling' food. EPOC + post-exercise appetite typically replace 25-40% of expended calories. Use as a perspective tool.

    29 min cycling 'burns' 285 kcal but adds ~70-115 kcal extra hunger across the day. Net deficit only if you don't compensate.

Worked Example

75 kg person wants to know how long to walk to burn off a 600-kcal dinner

Food kcal

600 kcal

Activity

Walking moderate (3.5 MET)

Body mass

75 kg

minutes = 600 / (3.5 × 75 × 0.0175) minutes = 600 / 4.59 minutes = 130.7 → ~131 minutes

131 minutes (2h 11m) walking to nominally burn the dinner. Caveat: in practice, walking for 2 hours produces 200-300 kcal of additional hunger that you may eat back. Use this number to reframe portion choice ('this dinner = 2h walking'), not as a literal cancel button.

Common Variations

Net vs gross kcal: this formula gives gross expenditure. Net (above resting BMR) is gross × (1 − 1/MET). Walking at 3.5 MET: gross 262 kcal/hr, net = 262 × (1 − 1/3.5) = 187 kcal/hr. Closer to truth for fat-loss accounting.
Ainsworth uses ages 19-64; values may overstate by 5-15% for older adults due to lower mitochondrial density.
EPOC (excess post-exercise oxygen consumption) adds 5-15% to total burn for moderate aerobic exercise, 15-25% for high-intensity intervals (Borsheim & Bahr 2003). This formula ignores EPOC.
Wearable trackers often inflate calorie burn by 15-30% (Shcherbina 2017). Trust this MET-based estimate over a Fitbit/Apple Watch readout for food-equivalence reasoning.

Try These Tools

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FAQ

Questions people ask next

The short answers readers usually want after the first pass.

How do you calculate how long to exercise to burn off food?
Use minutes_to_burn = food_kcal / (MET x mass_kg x 0.0175), where 0.0175 converts 1 kcal/kg/hr into per-minute terms. Look up the MET for your activity (walking 3.5, jogging 7.0, running 10 km/h 9.8, moderate cycling 7.5), use your body weight in kg, and the food's calorie count. For example, a 285 kcal slice of pizza for a 75 kg person cycling at 7.5 MET is 285 / (7.5 x 75 x 0.0175) = about 29 minutes.
What is a MET and where do the values come from?
A MET (Metabolic Equivalent of Task) is an activity-intensity multiplier where 1 MET equals resting energy expenditure, about 1 kcal/kg/hour or 3.5 ml O2/kg/min. Walking at 3.5 MET means 3.5 times resting. The MET values used here come from the Ainsworth 2011 Compendium of Physical Activities, which are population averages with roughly plus or minus 15% individual spread.
Does exercising really cancel out the calories I ate?
Not literally. This formula gives a theoretical gross expenditure, but EPOC and post-exercise appetite typically replace 25-40% of the calories you expend, so you only net a deficit if you do not eat them back. Treat the number as a perspective tool for portion choice (this dinner equals 2 hours of walking), not as a literal cancel button.
Should I trust my fitness tracker's calorie burn over this formula?
For food-equivalence reasoning, trust this MET-based estimate. Wearable trackers often inflate calorie burn by 15-30% (Shcherbina 2017). For fat-loss accounting, also consider net rather than gross calories: net = gross x (1 - 1/MET), so walking at 3.5 MET gives 262 kcal/hr gross but only about 187 kcal/hr net above your resting BMR.

Sources & References

General fitness estimates — not medical advice. Consult a healthcare professional for medical decisions.