# The Calculator

## Distance

How far did you walk?

## Duration/Pace

Enter either the walk duration or a pace/speed

# Description

## Introduction

This calculator predicts the calories burned by walking various distances at a variety of speeds for walkers of different weights.

Walking for exercise is very common. In addition to race walkers, and those using walking to lose weight, walking is used by many runners as an alternative or supplement to running. Its low-impact nature means it's particularly suitable when carrying an injury or a niggle.

Those who walk a lot for work or other reasons may wish to take the energy expenditure into account when planning diet or meals and increase their calorie intake accordingly.

# How It Works

## METs

The predictions made by this calculator are based on METs, Metabolic Equivalent of Task. METs are a common method of determining how much energy is expended by performing various activities. The activity type, the person's weight, and the activity's duration are all used to determine energy use. A single MET is roughly the amount of energy used by sitting down and relaxing. This baseline is used to work out the METs for other activities. As an example, walking at 3 mph requires roughly 3.5 times as much energy than sitting down. Thus, walking at 3 mph is equivalent to 3.5 METs

## METs and Calories (kcals)

Conversion from METs to Calories (kcals) is achieved as follows:

`Calories/kcals = activity (METs) x weight (kilograms) x duration (hours)`

The number of Calories/kcals used for a 3.5 MET activity performed for 2 hours by a person weighing 80 kilograms is:

`3.5 x 2 x 80 = 560 calories`

## Walking METs

We make use of the 2011 Compendium of Physical Activities Reference List for Walking in order to calculate METs used for walking at different speeds.

Where METs are not available for a certain speed, we use linear interpolation to derive an appropriate MET value.