how do I convert revolutions to miles?

I just finished doing a distance of 2173 in 40 minutes and burned 736 calories according to my eliptical. The stride is adjustable, but is set at 18 in.
I wear a heart rate monitor and keep my heart rate average between 140-150. today the average was 142, this mornitor tells me I only burned 369 calories. the heart rate monitor is set up with my age, weight, height, etc.
Something tells me that neither of these devices are accurate. I am thinking that the heart rate monitor is below what is actually being burned for calories and the eliptical is higher than what I actually burned.
not sure though....this is interesting what the distance would convert to because I am thinking since I usually run 2.5 that the distance 2173 is at least 2.5 miles...probably more like 3 miles...

I just did a crazy thing and contacted Pro Form and asked them. The answer is that for the 18" stride there are 1760 revolutions per mile.

So basically from the most recent post, with the phone call to the actual company, an 18" stride converts basically to 1 yard/ revolution. which would make the 1760 "yards" a mile. Good to know, because I was just looking this up after trying to keep in shape on my wife's elliptical, and in 30 minutes the display said I burned just over 500 calories, and did 2010 revolutions. Thanks for the help folks..

I don't even know when this conversation took pace of I have been looking for this information for a while now and I find this post very helpful. My elliptical has 18" stride length also so using your calculation is my typical workout is about abit more than 3 miles per workout. But when I go to gym with the type of elliptical that shows the miles for a siilar workout it says that I do between 4 and 5 miles depending on the intensity of the partcular day. I find this curious:0

Originally Posted by robert fogt

it probably differs between manufacturers, and you'd have to contact them for that information.

1 mile = 5280 feet

if 1 revolution was 2 steps (ie right foot then left foot) and your step is 2 foot long, then:

5280 feet / 2 feet = 2640 steps / 2 = 1320 revolutions

if you can measure how long each stride is, and determine for sure how many steps/strides in each revolution, then you could calculate fairly accurately.

That wouldnt work for exercise bikes, just elliptical machines.

very nice.. My problem only is the linear vel. Because the given on the problem are in revolution/ sec. How can i convert this revolution/sec to miles/sec??

The formula posted here is incorrect. The only reason I say this is because when I worked out at a gym while on vacation in January, the Lifefitness elliptical there shows miles, steps per minute, etc. and my Nike+ device, which I connect to the machine saves this information. So, looking back, it shows that in one workout, for example, I did 8.2 miles in 67 minutes.

Back at home, I use a older Pro-form elliptical to which I cannot connect Nike+, but I do the SAME type of workout (same intensity, same steps per minute, etc.). If I use the formula posted here, I calculate only doing 5.6875 miles. So, something is definitely wrong with the math.

I found a site that used the following calculation and it gets me closer to what the Lifefitness elliptical and Nike+ recorded.

First, measure the radius (r) of the encased wheel (this is the distance from the center to the outer edge). For improved accuracy, I measured from the center to the middle of the axle that attaches to the foot platforms. Multiply your result by 2 to get the diameter and then calculate the circumference (C=Pi x Dia).

Next, to calculate the miles per revolution you first need to convert C, which is in inches, to feet (divide C by 12). The resulting number is how many feet you have travelled in one complete turn of the flywheel (a revolution).

How many equal a mile? Well, there is 5280 feet in one mile so, divide 5280 by the feet travelled in one revolution to yield how many revolutions needed to go one mile.

Here is the calculation using the values I measureded on my home elliptical:

Radius=9 inches
Diameter=18 inches
Circumference (C)=56.5486677 inches
C/12=4.71238898 feet
5280/4.71238898= 1120.4508 revolutions needed to travel one mile

My machine at home records distance. In a recent 67 minute workout, the machine recorded 5,005. I need to multiply this number by two since I need to complete two full revolutions for each count.

5005 x 2 = 10010

10010/1120.4508= 8.9 miles

This number makes sense to me since my pace has improved since the workout at the gym in January.

[Mrs X]

Originally Posted by Milkwoman

My machine at home records distance. In a recent 67 minute workout, the machine recorded 5,005. I need to multiply this number by two since I need to complete two full revolutions for each count.

5005 x 2 = 10010

10010/1120.4508= 8.9 miles

This number makes sense to me since my pace has improved since the workout at the gym in January.

If you are indeed walking, this is pretty close to the olympic qualifying level. Just keep training for a couple more miles at that pace, and we'll see you there in 2016!

http://en.wikipedia.org/wiki/Racewalking

I have a PF900 and was perusing the internetwebs for discussion on converting the RPM to linear miles. I think the r2 x pi x 2 is likely the most accurate calc. One point to consider is that 'running' on an elliptical is basically like upright bicycling in that our feet are turning a wheel... now on my bike computer I need to enter the wheel diameter into the computer and it tells me the mileage for each trip, regardless of how much pedaling it took to get there (RPM equiv) or what gear I was in (work load)...

[Mrs X]

Originally Posted by Unregistered

I have a PF900 and was perusing the internetwebs for discussion on converting the RPM to linear miles. I think the r2 x pi x 2 is likely the most accurate calc. One point to consider is that 'running' on an elliptical is basically like upright bicycling in that our feet are turning a wheel... now on my bike computer I need to enter the wheel diameter into the computer and it tells me the mileage for each trip, regardless of how much pedaling it took to get there (RPM equiv) or what gear I was in (work load)...

The problem with this is that the distance you are walking or running is not the same distance as the flywheel travels, unless the tread revolution is exactly the same size as the circumference of the wheel. (Unlikely). The wheel is likely to turn a lot more often than the track on the treadmill.

[QUOTE=Mrs X;87777]If you are indeed walking, this is pretty close to the olympic qualifying level. Just keep training for a couple more miles at that pace, and we'll see you there in 2016!

That's funny. However, I don't "walk" on my elliptical...my pace is akin to running and I average a 7.75 - 7.90 minute mile. My elliptical has articulated petals, meaning they go up and down, allowing me a more natural gait. I don't keep my feet flat on the petals (as they would go numb after a while) but rather, keep them moving such that I am basically stepping as if I were actually running on the street.

(BTW...I also do HIIT training on the machine so combined with this pace are a series of tough resistance levels. Yeah, I'm a maniac. :-) )

Now, whether or not I am actually travelling the mileage I am calculating? That I am not 100% sure. It may be more "equivalent" miles, meaning, if I were indeed running on the street at this same pace, this is the equivalent distance I'd be travelling. I do know that my workouts are very intense, my heart rate fluctuates in-between cardio pace and fat-burning pace (depending upon where I am in the HIIT) and over the course of a year of doing this, I am in the best shape of my life, both heart-wise and muscle tone-wise.