# How accurate are pedometers?

**URL:** <https://boards.straightdope.com/t/how-accurate-are-pedometers/286018>\
**Category:** Factual Questions\
**Created:** [January 22, 2005, 1:48am UTC](https://boards.straightdope.com/t/how-accurate-are-pedometers/286018 "2005-01-22T01:48:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![legion](https://avatars.discourse-cdn.com/v4/letter/l/838e76/32.png) [@legion](https://boards.straightdope.com/u/legion)\
**Post date:** [January 22, 2005, 1:48am UTC](https://boards.straightdope.com/t/how-accurate-are-pedometers/286018/1 "2005-01-22T01:48:33Z")

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Or, more precisely, how accurate is the one I’ve been playing around with? It lets me enter my step length and weight and in return it tells me how far I’ve walked and how many calories I’ve burnt.

I can see the distance being pretty accurate but how does it determine the calories burnt? Is it just a best guess or is there an accepted method of working out the calories burnt by a person of X weight who walks y distance?

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**Author:** ![SavageNarce](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@SavageNarce](https://boards.straightdope.com/u/SavageNarce)\
**Post date:** [January 22, 2005, 2:15am UTC](https://boards.straightdope.com/t/how-accurate-are-pedometers/286018/2 "2005-01-22T02:15:12Z")

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Funny you should ask, since Cecil just posted [an article](http://www.straightdope.com/columns/050121.html) about walking and calories.

Your biggest problem is going to be averaging. If the pedometer is set to a stride length longer than your average stride, the figures it calculates will be too high; the opposite if your stride length is set too low. And the principle is basically a pendulum with a counter attached - it will register things like bending over the same as taking a step, and it won’t distinguish between walking uphill and walking downhill. I would use it as a general indicator, but its accuracy is certainly open to interpretation and adjustment.

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**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\
**Post date:** [January 23, 2005, 7:12am UTC](https://boards.straightdope.com/t/how-accurate-are-pedometers/286018/3 "2005-01-23T07:12:11Z")

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What about the pedometers that work by receiving signals from Global Positioning Satellites? I have one and quite often it gives some “wild” readings. Is it possible that it is NOT receiving the signals 100% of the time and so it “misses” part of the distance I walked?