Walking calories:
how pace and body weight change the number

How pace and body weight set walking calories

A 70 kg adult who walks briskly at 5.6 km/h for 45 minutes burns roughly 226 kcal. The same person strolling at 4 km/h for the same 45 minutes burns about 158 kcal. Two things drive that gap: how hard the body works at a given speed, and how much mass it has to move.

Both effects are captured by one number called a MET, short for metabolic equivalent. One MET is the energy you spend sitting quietly. A walk at 4 km/h costs about 3 times that, and a fast walk at 6.4 km/h costs about 5 times that. Multiply the MET by your weight and the hours walked and you have an estimate in kilocalories.

The figures here come from the widely used Compendium of Physical Activities, which lists typical MET values for level, firm ground. They describe an average adult, so treat the results as a sensible estimate rather than a measurement.

The MET formula for walking

Gross calories, which include the energy you would have used anyway while resting, are the number most apps and charts report.

If you only want the extra energy the walk added, subtract one MET: net calories = (MET − 1) × weight × hours. For the 45-minute brisk walk below that is 3.3 × 70 × 0.75 ≈ 173 kcal rather than 226, which is a fairer picture of what walking added to your day.

A walking-speed calculator turns a distance and a time into km/h, and the calorie calculators for easy and brisk walking apply the MET step for you. Use them to check any figure you do by hand.

Worked example: 45 minutes at a brisk pace

Take a 70 kg person walking at 5.6 km/h, which is a purposeful pace where conversation is still easy. The Compendium value for this speed is 4.3 MET.

At that pace the person covers 5.6 × 0.75 = 4.2 km. Drop the speed to 4 km/h at 3.0 MET and the 45 minutes cost 3.0 × 70 × 0.75 = 157.5, about 158 kcal, for 3 km of walking.

Calories per hour at different speeds

This table uses a 70 kg adult and one full hour of level walking. Scale the last column by your own weight divided by 70 for a quick personal figure.

Notice the jump at the top. Beyond about 7 km/h most people cannot keep a normal walking stride and either switch to technique walking or start jogging, which is why the MET rises steeply there.

Why a slower walk can cost the same per kilometre

A common surprise: for the same distance, walking slowly and walking briskly use nearly the same energy. A 5 km walk at 5.6 km/h takes about 54 minutes and costs 4.3 × 70 × 0.893 ≈ 269 kcal. The same 5 km at 4 km/h takes 75 minutes and costs 3.0 × 70 × 1.25 ≈ 263 kcal.

Speed raises the burn per minute, but you finish sooner, so the totals nearly cancel. What speed buys you is time. If you have 30 minutes, a faster pace gives more calories and more cardiovascular effort in that window. If you have no time limit, a longer walk does the same job.

How body weight scales the result

Calories scale in direct proportion to weight, because moving a heavier body takes more work. The table shows one hour at a brisk 6.4 km/h (5.0 MET) and one hour at an easy 4.0 km/h (3.0 MET).

A 100 kg walker therefore burns about 82% more than a 55 kg walker at the same speed. Per kilogram, though, everyone burns about the same: 5.0 kcal per kg per hour at 6.4 km/h.

This is why comparing your tracker with a friend's is rarely useful. The honest comparison is your own number across weeks, at the same pace and on a similar route.

Estimating speed from steps and stride

You do not need a GPS to know roughly how fast you walk. Speed equals the number of steps per minute multiplied by your stride length. A cadence of 100 steps a minute with a stride of 0.7 m gives 70 m a minute, or 4.2 km/h. A cadence of 120 with a 0.75 m stride gives 90 m a minute, or 5.4 km/h.

Many people find that around 100 steps a minute marks the start of a moderate pace and around 120 corresponds to a brisk one. Your own numbers will differ with height and leg length, so measure a stride by counting steps over a known 50 m stretch of track and dividing the distance by the count.

Once you know your speed, pick the closest row in the table above for the MET and multiply by your weight and time. A pedometer that records steps and minutes is enough for a reasonable estimate, even without a calorie display.

When the estimate can mislead

• Hills and stairs: a steady incline can raise the cost far above the flat-ground MET.
• Surfaces: sand, snow and loose gravel add effort, while a treadmill with no incline is a little easier than outdoors.
• Carrying load: a backpack adds to your effective weight for the whole walk.
• Stops: waiting at crossings or window-shopping counts as time but not as walking.
• Individual variation: stride length, fitness and efficiency can move the real figure 10 to 20% either way.

A watch with heart-rate data can refine the figure, but it is still an estimate. For health goals such as weight change, rely on trends over several weeks, and ask a doctor or dietitian before changing your diet or exercise if you have a medical condition.