Calories burned butterfly stroke calculator

Butterfly stroke is rated at 13.8 METs in the Compendium of Physical Activities, meaning it costs about 13.8 times as much energy as sitting still.

Body weight

Time spent

minutes

MET value

Prefilled from the Compendium of Physical Activities. Adjust it if you were working harder or easier.

Calories burned

507kcal

= Exact Calories burned butterfly stroke

Per hour at this intensity: 1014 kcal/h
Net of what you would have burned resting: 470 kcal
Same energy: 2122 kJ
Equivalent mass of pure fat: 56.4 g

Show the working

Body weight = 70
Time spent = 30
MET value = 13.8
kcal_per_min = 13.8 * 3.5 * 70 / 200 = 16.905
Calories burned = 16.905 * 30 = 507.15
Per hour at this intensity = 16.905 * 60 = 1014.3
Same energy = 507.15 * 4.184 = 2121.92
Equivalent mass of pure fat = 507.15 / 9 = 56.35
Net of what you would have burned resting = (13.8 - 1) * 3.5 * 70 / 200 * 30 = 470.4

Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.

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The formula

kcal per minute = MET x 3.5 x body weight in kg / 200
The 3.5 is oxygen uptake in mL per kg per minute at one MET; the 200 converts millilitres of oxygen to kilocalories at 5 kcal per litre.
total = kcal per minute x minutes

MET values are population averages for an activity performed at a stated intensity. Fitness, technique and terrain all move the real figure.

The gross figure includes the calories you would have burned anyway just by being alive; the net figure subtracts them, and is the more honest number for a weight-loss calculation.

This is a population formula, not a diagnosis. Individual metabolism, body composition and medical history all move the real answer, so treat the number as a starting point and talk to a clinician about anything that matters.

Frequently asked

How many calories does butterfly stroke burn per hour?

At 13.8 METs, a 70 kg person burns about 1014 kcal per hour. Heavier people burn proportionally more.

What is a MET?

A metabolic equivalent. One MET is the energy cost of sitting quietly, about 3.5 mL of oxygen per kilogram of body weight per minute, or roughly one kilocalorie per kilogram per hour.