Degrees? Percentages?
03-27-21, 05:50 PM
#51
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My Post 19 is corrected
I had degrees and angle interposed on my Post 19 of the fist page. Correct now. Sorry 'bout that'
03-29-21, 11:57 AM
#52
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For small angles tangent is almost the same as angle so all you have to do is change degrees to radians or multiply by 180÷pi=57 lets say 60
So if you have a 5 degrees × by 60 actually you dont need worry about the decimal place because we know its the same order of magnitude so after all that here is the synapses
Degrees to percent
Multipy by 6 and drop the 0
So if you have a 5 degrees × by 60 actually you dont need worry about the decimal place because we know its the same order of magnitude so after all that here is the synapses
Degrees to percent
Multipy by 6 and drop the 0
03-29-21, 12:01 PM
#53
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For small angles tangent is almost the same as angle so all you have to do is change degrees to radians or multiply by 180÷pi=57 lets say 60
So if you have a 5 degrees × by 60 actually you dont need worry about the decimal place because we know its the same order of magnitude so after all that here is the synapses
Degrees to percent
Multipy by 6 and drop the 0
So if you have a 5 degrees × by 60 actually you dont need worry about the decimal place because we know its the same order of magnitude so after all that here is the synapses
Degrees to percent
Multipy by 6 and drop the 0
03-29-21, 12:44 PM
#54
Junior Member
Using your calculator (or calculator app on your cell phone) to convert from degrees to percentage grade first use the “tan” key to find the tangent of the angle, then multiply that result times 100 to display it as a percentage value. That value is the “percentage grade”. To convert from a percentage grade to the angle of incline, first divide the percentage grade by 100 to convert it to its tangent, then use the arc-tangent key (labeled “atan”, or “tan-1”) to find its corresponding angle in degrees. Most calculators default to angular units of degrees. On some calculators you must choose between degrees and radians before using any of its trigonometric functions (such as tan and atan), in which case just make sure you had selected “degrees”. Also, to find the percentage grade from a topographical map or elevation chart, divide the change in elevation by the distance that you ride. That's the tangent. Then either multiply that (the tangent) by 100 to get the percentage grade, or use the atan key to find the angle of incline.
03-29-21, 01:01 PM
#55
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Percent is calculated on rise over run - or the amount up divided by the amount forward. if on a slope you proceed 1 unit of horizontal measurement, and it takes you up 1 unit of vertical measurement - then the slope is 100% . You do not need to know this but the distance upslope (along the hypotenuse) for this to happen is 1.414 units.
Simply put a 100% slope rises at 45 degrees.
A very rough but workable solution is to either multiply by 2 to convert degrees to percent, or divide by 2 to convert percent to degrees.
Simply put a 100% slope rises at 45 degrees.
A very rough but workable solution is to either multiply by 2 to convert degrees to percent, or divide by 2 to convert percent to degrees.
03-29-21, 01:14 PM
#56
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Approximately? In broad strokes?
Okay, here's an approximate rule that gets you within a percent or two for converting percent grade to degrees.
Originally Posted by msu2001la View Post
1 degree = 1.8%
2 degrees = 3.5%
3 degrees = 5.2%
4 degrees = 7.0%
5 degrees = 8.8%
6 degrees = 10.5%
7 degrees = 12.3%
8 degrees = 14.1%
9 degrees = 15.8%
10 degrees = 17.6%
Okay, here's an approximate rule that gets you within a percent or two for converting percent grade to degrees.
- Take percent grade, divide it in half. Add a tiny amount. That's the grade in degrees.
- To get percent grade from degrees? Double the degrees, and subtract a tiny amount.
Originally Posted by msu2001la View Post
1 degree = 1.8%
2 degrees = 3.5%
3 degrees = 5.2%
4 degrees = 7.0%
5 degrees = 8.8%
6 degrees = 10.5%
7 degrees = 12.3%
8 degrees = 14.1%
9 degrees = 15.8%
10 degrees = 17.6%
10 deg x 2 = 20; 10% off of that = 18%.
7% / 2 = 3.5; add 10% of that = 3.85 deg
But yeah, I'd just multiply or divide by 2 and forget the rest. The measurements you're starting with probably aren't that accurate anyway.
03-29-21, 01:56 PM
#57
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Max 35%,
For while you ride math in your head:
25% = 14 degrees. (Very near exact!)
10% < 6 degrees (5.71)
0.56 % per degree Edit: I got these mis-labeled!
1.78 degrees per %
The plot between percent and degrees is nearly a straight line between 0 and 30 degrees.
Edit: this is trig. Past 30 degrees and the conversion becomes less and less linear. (Down to 0.45 degrees per % at 45 degrees and 0.35 degrees per % at 60 degrees. Good thing is that we don't spend a lot of time riding at those angles.
25% = 14 degrees. (Very near exact!)
10% < 6 degrees (5.71)
0.56 % per degree Edit: I got these mis-labeled!
1.78 degrees per %
The plot between percent and degrees is nearly a straight line between 0 and 30 degrees.
Edit: this is trig. Past 30 degrees and the conversion becomes less and less linear. (Down to 0.45 degrees per % at 45 degrees and 0.35 degrees per % at 60 degrees. Good thing is that we don't spend a lot of time riding at those angles.
Possibly 1 road over 35%, top 7 are 30-35% per 'Treehugger worlds steepest streets'.
So for a real quick conversion, Double the percentage and subtract 10 of the intermediate result for a 1.8 factor to degrees.
Or half the degrees and add 10 percent. For easy remembering, it is the same factor as converting Celsius to Fahrenheit, but no adjustment for different zero point.
03-29-21, 03:54 PM
#58
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If the slope is simply referred to as a %, then it is most likely calculated as the change in height as a % of the length of road, be it wrong or right that is how it is interpreted in many regions, ie a slope of 1 in 5 meaning for every 5 steps one takes, they will rise by 1 step. With the then definition of a road that goes vertically up as having a slope of 100 %.
Of course there is not much difference if the measurements are for typical roads of less than 10 degrees, where tan(angle), rise/run and sin(angle) rise/(length of slope), are basically the same.
Just approximating the slope as the fraction the angle makes out of 90?
Okay for a couple of degrees, but at 10 degrees, which is possible for a road, we have 11% versus 17% if going with sin or tan
Of course there is not much difference if the measurements are for typical roads of less than 10 degrees, where tan(angle), rise/run and sin(angle) rise/(length of slope), are basically the same.
Just approximating the slope as the fraction the angle makes out of 90?
Okay for a couple of degrees, but at 10 degrees, which is possible for a road, we have 11% versus 17% if going with sin or tan
03-29-21, 09:16 PM
#59
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Thanks for the heads up tomato
so percent to degrees multiply by .6
For degrees to percent multiply by1.6
It only works for small angles
so percent to degrees multiply by .6
For degrees to percent multiply by1.6
It only works for small angles
03-30-21, 08:00 AM
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And to think I first thought this thread was about the % of BF members that had college degrees? 
03-31-21, 11:43 AM
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I just need to know how many "20mo's" ... cause at some point on every real hill, I start saying "do 20 more... ok, just do 20 more... juus duh tunney..."
