4 OPERATION
en-26
How to calculate a slope:
Tools Required:
Level (A), either 1 yard, or 1 meter long.
Tape measure (B).
With the level (A) positioned horizontally, measure the
distance (C) with tape measure (B). Use the chart to
calculate either the slope angle or the % grade of the
slope (D).
Figure 4D
C
A
B
D
Height (C)
Result (D)
Inches with 1 Yard Level (A)
Millimeters with 1 Meter Level (A)
Slope in Degrees
Slope Grade %
3
4.8
8.3
100
5.7
10.0
150
8.5
15
6
9.5
16.7
200
11.3
20.0
7.5
11.8
20.8
225
12.7
22.5
9
250
14
25.0
275
15.4
27.5
10
15.5
27.8
300
16.7
30.0
11
17.0
30.6
325
18.0
32.5
12
18.4
33.3
350
19.3
35.0
13
19.9
36.1
375
20.6
37.5
14
21.3
38.9
400
21.8
40.0
15
22.6
41.7
425
23.0
42.5
16
24
44.4
475
25.4
47.5
18
500
26.6
50.0
20
29.1
55.6
600
31.0
60.0
25
34.8
69.4
800
38.7
80.0
30
39.8
83.3
900
42.0
90
36
1000
45.0
100
