Introduction

This free calculator accurately predicts the calories and fat burned on a treadmill for a variety of distances, speeds, and user weights. It caters for different treadmill inclines/grades, age, and other factors, and can also estimate potential weight loss resulting from treadmill workouts.

Treadmills are a key component of many fitness routines, used by walkers, runners, and those somewhere in between. They're often incorporated into gym work, either as a warm-up, a cool-down, or part of the main routine. Treadmills are also popular with walkers and runners recovering from injury or during bad weather. They are also really useful for providing a low-impact alternative to outdoor running and a controlled and consistent environment for both longer runs and interval sessions.

Those who spend considerable time running or walking on the treadmill may find it useful to calculate energy expenditure so that dietary intake can be adjusted accordingly.

Weight loss

A massive benefit of treadmills for those seeking to lose weight is their accessibility, low-impact nature, and the ability to precisely control and monitor intensity and duration.

Being able to estimate calorie burn helps tailor an individualized weight-loss plan by ensuring that you're undertaking sufficient activity without overdoing things, thus supporting a healthy calorie deficit and fat loss. Gradual and sustainable weight loss means that you don't risk undue losses in strength, energy levels, or performance.

Weight gain

If your goal is to gain weight, especially lean mass, then you should factor in all forms of physical activity, including treadmill time. Even lighter treadmill sessions can impact your daily calorie expenditure and it's important to compensate accordingly.

Weight maintenance

If you're looking to maintain your current weight, then knowing how many calories are burned during treadmill sessions can help you fine-tune your diet and ensure a good energy balance.

Fuelling

Fuelling becomes important if you're undertaking longer or intense treadmill sessions. Knowing energy requirements can help you plan pre- and post-workout nutrition.

Running Calorie Calculator

We use a combination of METs Metabolic Equivalent of Task and research on outdoor running versus treadmill running to predict calorie burn.

METs

METs are simply a tool for figuring out how much energy you use during different activities. The basic idea is that sitting around relaxing is equivalent to a single MET. The METs for all other activities are determined with reference to this.

For example, if you're walking on a treadmill at 2.7 mph, you're using approximately 3.5 times more energy than when you're sitting still, so the MET value for treadmill running at this speed is 3.5.

Treadmill Walking and METs

For treadmill walkers under 60 we use the 2024 Compendium of Physical Activities Reference List for Walking in order to calculate METs used for walking on a treadmill at different speeds.

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

Treadmill Walking and Older Adults

For adults over 60, we use MET values from the 2024 Older Adult Compendium. This compendium was added in 2024 and caters for different calorie burn in older adults. This extra calorie burn is due to a range of factors, such as a reduction in lean body mass, a less efficient metabolism, and a reduction in general health.

Treadmill Running vs Outdoor Running

Unfortunately, the compendium doesn't provide sufficient or suitable MET values for treadmill running, so we have made use of other research to determine suitable values.

There are good reasons why treadmill running is easier than outdoor running:

• Wind Resistance: runners suffer no wind resistance on a treadmill. Wind resistance becomes a significant energy drain at faster running speeds.
• Surface:: a treadmill's surface is flat and consistent. Outdoors, terrain can vary even on flat roads, and runners must contend with cambers, cracks, curbs, slopes, and changing surfaces.
• Concentration: treadmill users need to concentrate far less. When running outside, it's necessary to concentrate on pace, obstacles, roads, etc.
• Consistent elevation: even when running on an incline, treadmills provide a consistent and predictable climb. Outside hills and slopes are rarely uniform.
• Biomechanics: the treadmill belt helps you poull your foot backwards during each stride. This reduces effort required from the hamstrings and glutes.
• Environment: on a treadmill in a gym the environment is controlled. When outside runners have to contend with weather and the effects of the weather.

A widely repeated rule is that running on a treadmill at 1% grade is equivalent to running on the flat outdoors. And this is an excellent rule of thumb based on research carried out in the 90s.

Research by Pugh considered how air resistance affects running by measuring VO₂ max as runners were subjected to different wind speeds. He determined that the cost of overcoming air resistance was about 8% at 21.5 kph (~13.36 mph) and about 16% at elite sprinting pace (~36 kph/22.4 mph).

To determine the reduction in energy requirements when no air resistance is experienced, we use a combination of the 1% rule and Pugh's research and apply adjustments to MET values for outdoor running.

Treadmill Running and Older Adults

In a similar manner, to determine calorie burn for treadmill runners over 60, we apply adjustments to MET values for outdoor running.

Curved Treadmills

Curved treadmills are becoming more popular and commonplace in gyms. Fortunately, the compendium provides suitable MET values for curved treadmill running.

Although there are no entries for curved treadmill METs in the older adults compendium, we are able to derive a multiplicative factor from other running values in the compendia and apply this to the values for younger adults.

Note that the curved treadmill setting only applies to treadmill runs, and grade/angle inputs are ignored if the curved option is selected.

METs and Calories (kcal)

Conversion from METs to calories (kcal) is carried out as follows:

Calories (kcal) = activity (METs) x weight (kilograms) x duration (hours)

The number of Calories/kcal used for a 4.5 MET activity performed for 1.5 hours by a person weighing 60 kilograms is:

4.5 x 1.5 x 60 = 405 calories

Treadmill Grade and Calories

The calculator allows you to estimate the effect of an increased treadmill grade on treadmill walking/running.

Treadmill Walking and Grade

For treadmill walking at a grade, we use the Load Carriage Decision Aid (LCDA) walking equation:

EE = 1.44 + 1.94S0.43 + 0.24S4 + 0.34SG(1 - 1.051 - 1.1G + 32)

where

EE = Energy Expenditure in watts per kilogram
G = Grade, expressed as a percentage
S = speed in meters per second

Treadmill Running and Grade

Treadmill grade represents increase in vertical units per 100 horizontal units.

So, a grade of 2% means that for each 100 meter walked or run, you will climb 2 meters.

To determine the impact of a treadmill incline on calorie burn we use research by D. B. Dill. Dill's research showed that each meter climbed on a run requires 1.31 millilitres of oxygen per kilogram of weight.

We first convert treadmill grade to vertical gain in meters:

Vertical gain = Run distance × Treadmill grade ÷ 100

We can then work out the overall oxygen requirements for the vertical component of the walk/run:

Oxygen requirements in millilitres = elevation gain × weight in kilograms × 1.31

Each litre of oxygen used burns roughly 5 kilocalories. So to get calories burned due to the climb:

Kilocalories burned = elevation gain × weight in kilograms × 1.31 ÷ 1,000 × 5

Treadmill vs. Outdoor Running/Walking

If your're walking outside, then we suggest using our walking calorie calculator or our hiking calorie calculator.

And if you're running outside, then we recommend using our dedicate outdoor running calorie calculator.

Using the rule of thumb that 3,500 calories is roughly equal to one pound of fat, we simply estimate that:

Weight loss (lbs) = Calories ÷ 3,500

or in metric:

Weight loss (kg) = kilojoules ÷ 32,217

For example, if somebody weighing 180 pounds does a treadmill run of 6 miles in one hour then they will burn about 739 kcal / 3,092 kJ and therefore lose approximately:

739 ÷ 3,500 ≈ 0.21 lbs

or in metric:

3,092 ÷ 32,217 ≈ 0.96 kg

Weight

Enter your weight in pounds, kilograms, or pounds and stones. Your weight will impact your energy requirements, with greater weights requiring more energy.

Distance

Specify how far you walked or ran in miles, kilometers, or meters.

Duration/Pace

Enter the treadmill time or yoru pace/speed in miles per hour, kilometers per hour, minutes per mile, or minutes per kilometer. The greater the exercise duration, the greater the calorie burn.

Age

Check the "Over 60" checkbox if appropriate. Older adults tend to burn more calories for similar exercise.

Grade/Angle

You can also specify a treadmill grade or an angle in degrees. The greater the gradient, the more energy is required.

Curved treadmill

Check the "Curved treadmill" checkbox. You'll burn significantly more calories on a curved treadmill.

Types of Treadmill Sessions

Useful tools

Weight vs. pace calculator. Discover how much faster you could run by losing weight.

Treadmill pace/speed conversion table. At-a-glance conversions between speed and pace.

Other calorie calculators

Calorie calculator for runners. Includes hill, age and backpack options.

Calorie calculator for walkers. Including Nordic walking.

Calorie calculator for hikers. A specialized calculator for the peculiarities of hiking.

Calorie calculator for cyclists. An outdoor cycling calculator with climb options.

Stationary bike calorie calculator. A specialized calculator for indoor bikes, based on riding intensity and power.

Calorie calculator for swimmers. With popular strokes and water activities.

Calorie calculator for rowers. A calculator for ergometers based on rowing intensity, power output, or split time.

Further reading

2024 Compendium of Physical Activities

2024 Compendium of Physical Activities Reference List for running activities

2024 Compendium of Physical Activities for Older Adults

Energy costs of human activities in adults aged 60 and older

2024 Adult Compendium of Physical Activities: A third update of the energy costs of human activities

A brief history of the Compendium of Physical Activities