Rafter Tips

Rafter Chart
		Length Per Foot Run
Angle in degrees	Rise^¨	Common Rafters	Hip/Valley Rafters
4 ¾	1	12.04”	17.00”
9 ½	2	12.16”	17.09”
14	3	12.37”	17.23”
18 ½	4	12.65”	17.44”
22 ½	5	13.00”	17.69”
26 ½	6	13.42”	18.00”
30 ¼	7	13.89”	18.36”
33 ¾	8	14.42”	18.76”
37	9	15.00”	19.21”
39 ¾	10	15.62”	19.70”
42 ½	11	16.28”	20.22”
45	12	16.97”	20.78”
47 ¼	13	17.69”	21.38”
49 ½	14	18.44”	22.00”
51 ¼	15	19.21”	22.65”
53	16	20.00”	23.32”
54 ¾	17	20.81”	24.02”
56 ¼	18	21.63”	24.74”
57 ¾	19	22.47”	25.47”
59	20	23.32”	26.23”
60 ¼	21	24.19”	27.00”
61 ½	22	25.06”	27.78”
62 ½	23	25.94”	28.58”
63 ½	24	26.83”	29.39”
64 ½	25	27.73”	30.22”
65 ¼	26	28.64”	31.05”
66	27	29.55”	31.98”
66 ¾	28	30.46”	32.74”
67 ½	29	31.38”	33.60”
68 ¼	30	32.31”	34.47”

^¨The length indicated for Rise is needed for each 12 inches of horizontal measurement (RUN).

Example: 21 ft. wide building with 4” Rise Roof: Common rafter (RUN) is 21 Ft. divided by 2 = 10.5 Ft. 12.65 inches (from 4” rise on table) x 10.5 Ft. (RUN) = 132.83” (132 13/16”) needed for rafter length, then add on for overhang. Figure Hip Valley the same way.

Conversion Table
Inches	Decimal	Inches	Decimal
1/32	0.03215	17/32	0.53125
1/16	0.0625	9/16	0.5625
3/32	0.09375	19/32	0.59375
1/8	0.125	5/8	0.625
5/32	0.15625	21/32	0.65625
3/16	0.1875	11/16	0.6875
7/32	0.21875	23/32	0.71875
1/4	0.25	3/4	0.75
9/32	0.28125	25/32	0.78125
5/16	0.3125	13/16	0.8125
11/32	0.34375	27/32	0.84375
3/8	0.375	7/8	0.875
13/32	0.40625	29/32	0.90625
7/16	0.4375	15/16	0.9375
15/32	0.46875	31/32	0.96875
1/2	0.5	32/32	1

Rafter Chart