About Exercise Duration Calculator

Calculate calories burned, fat loss, and recovery time for different exercises. Part of the DevTools Surf developer suite. Browse more tools in the Calculators collection.

Use Cases

• Calculate calories burned during a specific workout for diet tracking
• Find how long to exercise to burn off a specific meal
• Compare calorie burn across different exercise types at the same duration
• Determine exercise duration needed to reach a weekly calorie deficit target

Tips

• Select your exercise type from the predefined list — MET (Metabolic Equivalent of Task) values differ significantly between walking (3.5 METs) and running at 6 mph (10 METs)
• Enter your exact body weight — calorie burn scales linearly with weight, so this is the most impactful input for accuracy
• Use the heart rate zone target to find the duration at which you reach your target zone — heart rate zones indicate exercise intensity independent of speed

Fun Facts

• The MET (Metabolic Equivalent of Task) system was developed in the 1960s to standardize physical activity measurement. A MET value of 1 represents resting energy expenditure (approximately 1 kcal per kg per hour). The 2011 Compendium of Physical Activities lists METs for over 800 activities.
• HIIT (High-Intensity Interval Training) burns 25-30% more calories than moderate continuous exercise per minute of workout, according to a 2019 British Journal of Sports Medicine review. The afterburn effect (EPOC — excess post-exercise oxygen consumption) can elevate metabolism for up to 24 hours post-HIIT.
• The CDC recommends 150 minutes of moderate-intensity aerobic activity per week (30 minutes, 5 days) for adults — a guideline based on epidemiological research showing optimal mortality risk reduction. Below this threshold, even adding 10 minutes per week has measurable health benefits.

FAQ

Are calorie burn estimates accurate?

MET-based estimates are accurate to within 10-20% for most people at steady-state exercise. Individual variation (fitness level, body composition, age, efficiency) causes the actual range. Wearable devices add heart rate data to improve accuracy; lab metabolic testing is most precise.

What is the difference between calories burned during exercise vs total daily calories?

Exercise typically accounts for 5-30% of total daily energy expenditure (TDEE). Basal metabolic rate (BMR) — energy for basic body functions at rest — accounts for 60-70%. Non-exercise activity thermogenesis (NEAT — fidgeting, walking) adds another 15-20%. Exercise alone rarely creates sufficient deficit without dietary adjustment.

Does muscle mass affect calorie burn during exercise?

Slightly — more muscle mass increases resting metabolism but has minimal impact on per-minute calorie burn during most aerobic exercise. Body weight (which includes muscle) directly affects calorie burn. Resistance training's primary calorie-burning benefit is the hours-long post-exercise metabolic elevation.