About

Unlike cardio exercises, anaerobic movements like push-ups are difficult to track using standard heart rate monitors. This tool abandons generic estimates in favor of a work-physics approach. By calculating the mechanical work performed-lifting roughly 68% of your body mass against gravity over a set distance-we can derive the precise energy expenditure in Joules before converting to Kilocalories.

This calculator also accounts for the human body's mechanical efficiency (approx. 20%), meaning for every unit of mechanical work produced, the body actually burns five units of metabolic energy. The results are contextualized into "Food Equivalents" to offer a tangible perspective on the effort required to burn off common snacks.

Formulas

The core calculation treats the push-up as a work function against gravity. We assume the center of mass travels approximately 0.3 meters per repetition and the effective load is 68% of total body weight.

Force = Weight_kg × g × 0.68

Work_Joules = Force × 0.3_m × Reps

To convert mechanical work to metabolic cost, we apply the conversion factor (1 kcal = 4184 J) and the efficiency factor (20%):

Kcal = Work_Joules4184 ÷ 0.20

Reference Data

Body Weight (lb)	Reps (Standard Tempo)	Work (Joules)	Calories Burned	Food Equivalent
150	20	2,760	3.3	1/20 Apple
150	50	6,900	8.2	1 Gummy Bear
150	100	13,800	16.5	2 Almonds
180	50	8,280	9.9	1.5 Gummy Bears
180	100	16,560	19.8	1/4 Slice Bread
200	50	9,200	11.0	1 Cracker
200	100	18,400	22.0	1/3 Apple
200	500	92,000	110.0	1 Banana

Frequently Asked Questions

Push-ups are a strength exercise, not an aerobic one. While they build muscle and increase metabolic rate long-term (EPOC), the immediate energy cost of a single rep is small. 50 push-ups might take 2 minutes, whereas a 2-minute run involves moving the entire body weight thousands of times.

Yes. Explosive (fast) push-ups require greater force generation (F=ma) to accelerate the body, recruiting fast-twitch fibers which are less efficient, thus burning slightly more energy. Slow, controlled reps increase time-under-tension but may burn fewer total calories per minute.

Biomechanics studies show that in a standard plank position, your hands support approximately 68% of your body weight, while your feet support the remaining 32%.

No. For knee push-ups, the load factor drops from ~68% to approximately 54% of body weight, reducing the calorie burn by roughly 20-25%.