Researchers may have discovered that spending an hour in a hot bath can burn as many calories as a 30 minute walk, but, tempting as it may be, spending half your life in the tub probably isn’t practical. But just how many calories do you burn walking? Many of us now track every step we take, but what does that step count really mean? Ready to find out how exactly many calories are burned walking? Well, we’ve found a handy formula which takes out the guesswork.
Calorie counting apps are all well and good, but few give you more than a passing indication of the number of calories used walking. Why? Because some of the most commonly used formulas fail to account for individual factors which affect the rate at which we burn calories, like height and (in some cases) weight.
The good news? You could be burning more calories than you thought, especially if you’re on the petite side. Researchers who analysed multiple data sets published over the past 50 years discovered that standard calculations underestimated calorie burn in 97% of cases. Your height makes more of a difference than it’s been given credit for, according to Peter Weyand, the study’s co-author, who helped to come up with the new formula. “The taller you are, the less energy it takes to walk a mile, or the slower the rate you burn calories while walking at the same speed compared to someone who is shorter,” he explains.
To use the formula, which measures the number of calories burned per minute during level walking and works for all ages, you’ll need to know your walking speed. Try the free Map My Walk app, which can record the speed and duration of your walks, plotting them on a nifty interactive map.
How to calculate the number of calories burned walking:
Here’s the formula you need to know:
Calories burned per minute = (0.035 * body weight in kg) + ((Velocity in m/s ^ 2) / Height in m)) * (0.029) * (body weight in kg)
Don’t worry – it’s not as complicated as it looks. Let’s say you’re 1.6m tall, weigh 60kg and typically walk at 1.4 metres per second (that’s about 3.1mph).
First, multiply your body weight in kilograms (i.e. 60) by 0.035.
0.035 x 60 = 2.1
Now, square your velocity (or speed) in metres per second, i.e. multiply it by itself.
1.4 x 1.4 = 1.96
Now, divide the result by your height in metres (i.e. 1.6).
1.96 ÷ 1.6 = 1.225
The formula now looks like this:
Calories burned per minute = (2.1) + ((1.96)/1.6)) * (0.029) * (60)
Calories burned per minute = (2.1) + (1.225) * (0.029) * (60)
2.1 + 1.225 = 3.325
3.325 x 0.029 = 0.096425
0.096425 x 60 = 5.7855
This means that someone of your height and weight will typically burn 5.8 calories per minute when walking on a level surface at a speed of 1.4m/s or 3.1mph. A standard formula accounting for weight alone would give you an estimated figure of 4 calories burned per minute.
Whilst the formula can’t account for gradient or fitness levels, scientists claim it is much more accurate than the algorithms typically used by calorie burn ‘calculators’, treadmills and fitness apps.