Cycling calorie calculator: how many calories does an hour of cycling burn?

It’s the question people ask most, so let’s answer it straight away: someone weighing 70 kg who pedals for an hour at 20 km/h burns about 560 kcal. In the same hour, running gets you 651 kcal and brisk walking 336 kcal.

But calories per hour can be misleading on a bike, because you cover twice as much ground as you would running. Look at it per kilometre and the picture flips:

• Cycling: about 28 kcal per kilometre
• Running: about 65 kcal per kilometre

So riding 20 kilometres burns fewer calories than running 10. Where the bike wins isn’t calories: it’s the low load on your joints and the fact that you can keep going for far longer distances. The cycling calorie calculator above reproduces these numbers for your own weight and pace.

Gross calories burned in a one-hour ride by someone weighing 70 kg:

• 12 km/h (leisurely): 280 kcal
• 18 km/h (easy pace): 476 kcal
• 20 km/h (moderate pace): 560 kcal
• 24 km/h (fast): 700 kcal
• 28 km/h (very fast): 840 kcal
• 35 km/h (racing pace): 1,176 kcal

What stands out is that the increase isn’t proportional to speed: double your speed from 12 to 24 km/h and the calories burned more than double. The reason is air resistance, which we explain below.

The surface and the kind of riding matter at least as much as speed. Again for 70 kg and one hour:

• Commuting: 476 kcal
• Mountain biking, general: 595 kcal
• Mountain biking, climbing: 980 kcal
• Spinning class: 630 kcal
• Exercise bike: 476 kcal

An hour of hard climbing comes out 75% higher than an hour on a flat road. That’s exactly why the cycling calorie calculator has a “Type of ride” list: each option maps to its own measured row, not an estimated multiplier.

The big number the calculator gives you is the gross figure: the total energy your body uses while you pedal. But if you’d spent that hour on the sofa, you’d still have been breathing and your heart would still have been beating, so you’d have burned some calories anyway. The extra cost of the ride is whatever’s left once you take that resting share out. We call that the net figure.

For a one-hour ride at 20 km/h, someone weighing 70 kg burns 560 kcal gross and 490 kcal net. The 70 kcal in between is energy you’d burn in that hour even if you did nothing at all.

Which one should you use? If you’re just curious, the gross number is fine. But if you’re adding your ride on top of your daily calorie needs, use the net number, because your daily needs already include your resting expenditure for those hours. Add the gross figure and you count the same calories twice.

We need to be honest here: a cycling calorie estimate is noticeably weaker than one for running or walking. That’s also why cycling calculators online give such wildly different results. There are two main reasons, and we’re not hiding either of them.

1. On the flat, most of your energy goes into pushing through the air

When you run, most of your energy goes into carrying your own body forward, which is why the cost per kilometre stays fairly constant. On a bike, the wheels carry your weight. On a flat road, most of the power you need goes into overcoming air resistance, and that resistance climbs steeply with speed: double your speed and the drag roughly quadruples.

In practice, this means the wind, your riding position and especially whether you’re sitting behind a group can change your energy use a lot. In a peloton you burn noticeably less at the same speed. The Compendium, our source, says so openly: it describes the same row as both “16–19 mph, not drafting” and “over 19 mph, drafting”. In other words, behind a group you can hold a higher speed for the same cost.

If you’re riding into a headwind, what you actually burn is higher than the number here; with a tailwind or inside a group, it’s lower.

2. Body weight doesn’t behave the way the formula assumes

The MET × weight calculation we use assumes that energy use rises in direct proportion to body weight. For running and walking that’s a good approximation, because you lift your own body with every step. On a flat road on a bike, what counts isn’t your mass but your frontal area, the surface you present to the wind, and that doesn’t grow in proportion to weight.

The upshot: for heavier riders, this tool tends to put the figure a little high on the flat and low on climbs. If most of your riding is uphill, choose “Mountain biking — climbing”; that row was measured going uphill in the first place.

If you really want an exact number, the only way is a power meter. Work measured in watts takes all of this guesswork out of the picture.

We treat indoor riding separately because there’s no real distance involved. The “km” on an exercise bike’s screen is worked out from how many times the flywheel turns, so it can’t be compared with distance covered on the road. That’s why, for the exercise bike, spinning and interval options, the cycling calorie calculator only asks for time.

For someone weighing 70 kg, one hour comes to 476 kcal on an exercise bike, 630 kcal in a spinning class and 616 kcal in an interval session. The 32% gap between spinning and an ordinary exercise bike reflects how hard an instructor-led class pushes you.

Why does the gym machine show a different number? Most exercise bikes don’t ask for your weight, or they use a default value. A machine that doesn’t know your weight can’t calculate calories; what it does is produce a rough guess from the resistance level. A calculation that uses your actual weight is more reliable than a screen that never asks for it.

Contrary to what many people think, yes, but it depends on how much assistance you use. For someone weighing 70 kg, in one hour:

• Assist off: 476 kcal
• Light assist: 420 kcal
• High assist: 280 kcal

Even on the highest setting, you’re burning about as much as a brisk walk. On light assist it’s only slightly lower than a normal bike, because e-bikes are heavy and the motor makes pedalling easier rather than doing it for you. The real effect of an e-bike isn’t to wipe out the effort; it’s that it gets you riding for longer and more often.

Here’s the formula we use: kcal = MET × weight (kg) × time (hours). MET is a measure of how many times more energy an activity uses than resting does. The net figure is (MET − 1) × weight × time.

We take the MET values from the 2024 Adult Compendium of Physical Activities (Herrmann et al., Journal of Sport and Health Science, 2024); you can browse the full table at pacompendium.com. We show which row we used, with its Compendium code, below the result, so you can check it against the source if you want to.

There’s one difference from running: in our running calculator, if your speed falls between two steps we interpolate, because the energy cost of running rises almost linearly with speed. On the bike we don’t. Air resistance makes the relationship non-linear, and the Compendium’s cycling rows were measured as speed ranges, not individual speeds. Splitting a value inside a range would mean inventing precision that was never measured, so instead we use the nearest step and tell you which one it is.

Results from the cycling calorie calculator are based on population averages measured in healthy adults. Two people of the same weight riding at the same speed can differ by ±20% in what they actually burn, depending on fitness, riding efficiency, tyres and surface. On a bike, wind and group riding come on top of that, so for the reasons explained above, a cycling estimate sits in a wider range than a running one.

The tool isn’t valid for under-18s, people who are pregnant or breastfeeding, or anyone with a chronic condition that affects their metabolism. It isn’t a diet or weight-loss plan either: it tells you how much you burned, not how much you should eat.