The relationship between the pitch, fall or rise and the horizontal, is the relationship between the opposite and the adjacent sides of a right angled triangle.
This is known as the tangent of the angle. (tan ɸ) with the opposite side being the rise and the adjacent side the horizontal distance.
Enter any two values on the illustration for live calculations.
°
1 in
18.2A Rafter, Hip and Rise Chart
Pitch | Rafter length | Hip/Valley Length | Vertical Rise | Valley Angle |
---|---|---|---|---|
per metre span | per metre span | per metre span | ||
0.5 | 1.000 | 1.414 | 0.009 | 179° |
1 | 1.000 | 1.414 | 0.017 | 179° |
1.5 | 1.000 | 1.414 | 0.026 | 178° |
2 | 1.001 | 1.415 | 0.035 | 177° |
3 | 1.001 | 1.415 | 0.052 | 176° |
4 | 1.002 | 1.416 | 0.070 | 174° |
5 | 1.004 | 1.417 | 0.087 | 173° |
6 | 1.006 | 1.418 | 0.105 | 172° |
7 | 1.008 | 1.420 | 0.123 | 170° |
8 | 1.010 | 1.421 | 0.141 | 169° |
9 | 1.012 | 1.423 | 0.158 | 167° |
10 | 1.015 | 1.425 | 0.176 | 166° |
11 | 1.019 | 1.428 | 0.194 | 164° |
12 | 1.022 | 1.430 | 0.213 | 163° |
13 | 1.026 | 1.433 | 0.231 | 162° |
14 | 1.031 | 1.436 | 0.249 | 160° |
15 | 1.035 | 1.439 | 0.268 | 159° |
16 | 1.040 | 1.443 | 0.287 | 158° |
17 | 1.046 | 1.447 | 0.306 | 156° |
18 | 1.051 | 1.451 | 0.325 | 155° |
19 | 1.058 | 1.456 | 0.344 | 153° |
20 | 1.064 | 1.460 | 0.364 | 152° |
21 | 1.071 | 1.465 | 0.384 | 151° |
22 | 1.079 | 1.471 | 0.404 | 149° |
23 | 1.086 | 1.477 | 0.424 | 148° |
24 | 1.095 | 1.483 | 0.445 | 147° |
25 | 1.103 | 1.489 | 0.466 | 145° |
26 | 1.113 | 1.496 | 0.488 | 144° |
27 | 1.122 | 1.503 | 0.510 | 143° |
28 | 1.133 | 1.511 | 0.532 | 141° |
29 | 1.143 | 1.519 | 0.564 | 140° |
30 | 1.155 | 1.528 | 0.577 | 139° |
31 | 1.167 | 1.537 | 0.601 | 137° |
32 | 1.179 | 1.546 | 0.625 | 136° |
33 | 1.192 | 1.556 | 0.649 | 135° |
34 | 1.206 | 1.567 | 0.675 | 133° |
35 | 1.221 | 1.578 | 0.700 | 132° |
36 | 1.236 | 1.590 | 0.727 | 131° |
37 | 1.252 | 1.602 | 0.754 | 130° |
38 | 1.269 | 1.616 | 0.781 | 128° |
39 | 1.287 | 1.630 | 0.810 | 127° |
40 | 1.305 | 1.644 | 0.839 | 126° |
41 | 1.325 | 1.660 | 0.869 | 125° |
42 | 1.346 | 1.677 | 0.900 | 124° |
43 | 1.367 | 1.694 | 0.933 | 122° |
44 | 1.390 | 1.712 | 0.966 | 121° |
45 | 1.414 | 1.732 | 1.000 | 120° |
46 | 1.440 | 1.753 | 1.036 | 119° |
47 | 1.466 | 1.775 | 1.072 | 118° |
48 | 1.494 | 1.798 | 1.111 | 117° |
49 | 1.524 | 1.823 | 1.15 | 115° |
50 | 1.556 | 1.849 | 1.192 | 114° |
51 | 1.589 | 1.877 | 1.235 | 113° |
52 | 1.624 | 1.907 | 1.280 | 112° |
53 | 1.662 | 1.939 | 1.327 | 111° |
54 | 1.701 | 1.973 | 1.376 | 110° |
55 | 1.743 | 2.010 | 1.428 | 109° |
56 | 1.788 | 2.049 | 1.483 | 108° |
57 | 1.836 | 2.091 | 1.540 | 107° |
58 | 1.887 | 2.136 | 1.600 | 106° |
59 | 1.942 | 2.184 | 1.664 | 105° |
60 | 2.000 | 2.236 | 1.732 | 104° |
65 | 2.366 | 2.569 | 2.145 | 100° |
70 | 2.924 | 3.09 | 2.747 | 97° |
75 | 3.864 | 3.991 | 3.732 | 94° |
80 | 5.759 | 5.845 | 5.671 | 92° |