Measuring Percent of Grade: How to Determine 5% Grade

  • Thread starter F3 guy
  • Start date
  • Tags
    Percent
In summary, the conversation discusses how to measure a percent of grade, specifically in a ratio or linear measurement. It is calculated by comparing the vertical rise to the horizontal run, and a percentage can be obtained by multiplying the grade by 100. The conversation also explains that 5% of a foot is 0.6 inches, 5% of a yard is 1.8 inches, and 5% of a mile is 88 yards. It is also mentioned that a 100% grade is equivalent to a 45 degree angle. Finally, the speaker expresses gratitude for the helpful information.
  • #1
F3 guy
2
0
I hope a message board of this caliber can help me.

Here is my problem. How does one measure a percent of grade? Specifically in a ratio or in a liner measurement how would I know what a 5% grade is? I need to ensure a field is within 5%, is that so many inches out of level in a foot, yard, or mile?

Any help would be greatly appreciated.
 
Mathematics news on Phys.org
  • #2
% grade is calculated by comparing vertical rise to horizontal run. Imagine walking 100 feet horizontally while gaining 5 feet vertically; 5 feet is 5% of 100 feet, so the grade is 5%.

- Warren
 
  • #3
In other words, if you measure the height rise h over a horizontal distance d, then the grade is h/d. If you want a percentage, multiply this number by 100.

For example, if the field rises 1 foot over a 20 foot horizontal distance, the grade is 1 in 20, or 1/20. The percentage grade is 1/20 multiplied by 100, which is 5%.
 
  • #4
I need to ensure a field is within 5%, is that so many inches out of level in a foot, yard, or mile?

5% of a foot is 5% of 12 in= 0.6 inches.

5% of a yard is 5% of 36 in= 1.8 inches (exactly 3 times 0.6 since a yard is 3 feet).

5% of a mile is 5% of 5280 ft so 5280(0.6)= 3168 in.= 264 ft= 88 yards.
 
  • #5
So, a 100% grade is 45 degrees?
 
  • #6
DaveC426913 said:
So, a 100% grade is 45 degrees?

That's right.
 
  • #7
I knew this was the right place to ask! Thank you all very much.
 

Related to Measuring Percent of Grade: How to Determine 5% Grade

1. What is percent grade and why is it important?

Percent grade is a measure of the steepness or slope of a surface, expressed as a percentage. It is important because it helps determine the difficulty of a path or road, the potential for erosion, and the required effort for construction or maintenance.

2. How do I calculate the percent grade?

To calculate the percent grade, you need to determine the rise (vertical change) and run (horizontal distance) of the slope. Then, divide the rise by the run and multiply by 100 to get the percent grade. For example, if the rise is 5 feet and the run is 100 feet, the percent grade would be (5/100)*100 = 5%.

3. What is a 5% grade equivalent to in degrees?

A 5% grade is equivalent to a 2.86 degree angle. This can be calculated by taking the inverse tangent of 5% (0.05) using a scientific or graphing calculator.

4. How can I measure the percent grade of a road or trail?

You can measure the percent grade of a road or trail using a surveying instrument called a clinometer, which measures angles of inclination. Alternatively, you can use a smartphone app that utilizes the phone's accelerometer to measure slopes.

5. What are some common examples of a 5% grade?

A 5% grade is considered a moderate slope and is commonly found on hiking trails, bike paths, and residential roads. It is also frequently used in the construction of roads and highways as it provides a good balance between ease of construction and safe driving conditions.

Similar threads

Replies
1
Views
2K
  • General Math
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
33
Views
476
Replies
1
Views
2K
  • General Engineering
Replies
12
Views
1K
  • Biology and Chemistry Homework Help
Replies
2
Views
2K
Replies
40
Views
3K
  • General Math
Replies
1
Views
1K
  • STEM Academic Advising
Replies
32
Views
719
  • Mechanical Engineering
Replies
5
Views
1K
Back
Top