Chord factor charts
Chord factors are pure numbers which when multiplied by the radius of the dome give you the length of a strut. If your dome requires 3 different lengths, then you will have 3 distinct chord factors, one for each length.
Below we provide chord factors for geodesic domes of frequency 1V up to 8V, based on method 1 (Icosa-based). You will also find the bend angles for each strut length.
1V geodesic dome chord factor |
||
| 15 3-sided faces | ||
| A X 25 | 1.05146 | 31.72° |
2V geodesic dome chord factors |
||
| 40 3-sided faces | ||
| A X 35 | 0.61803 | 18° |
| B X 30 | 0.54653 | 15.86° |
3V geodesic dome chord factors |
||
| 3/8 =75 3-sided faces, 5/8 = 3-sided faces 105 faces |
||
| A X 30 | 0.34862 | 10.04° |
| B X 40 | 0.40355 | 11.64° |
| C X 50 | 0.41241 | 11.90° |
4V 1/2 method 1 dome chord factors |
||
| 160 3-sided faces | ||
| A X 30 | 0.25318 | 7.27° |
| B X 30 | 0.29524 | 8.47° |
| C X 60 | 0.29453 | 9.35° |
| D X 70 | 0.31287 | 9° |
| E X 30 | 0.32492 | 8.59° |
| F X 30 | 0.29859 | 9.35° |
5V geodesic dome chord factors |
||
| 7/15 =225 3-sided faces 8/15 = 3-sided faces 435 faces |
||
| A X 30 | 0.19814743 | 5.69° |
| B X 30 | 0.23179025 | 6.48° |
| C X 60 | 0.22568578 | 6.65° |
| D X 60 | 0.24724291 | 6.66° |
| E X 50 | 0.25516701 | 7.04° |
| F X 50 | 0.24508578 | 7.05° |
| G X 30 | 0.26159810 | 7.10° |
| H X 30 | 0.23159760 | 7.33° |
| I X 10 | 0.24534642 | 7.52° |
6V geodesic dome chord factors |
||
| 360 3-sided faces | ||
| A X 30 | 0.16256722 | 4.66° |
| B X 30 | 0.19047686 | 5.22° |
| C X 60 | 0.18190825 | 5.38° |
| D X 90 | 0.20281969 | 5.47° |
| E X 30 | 0.1873834 | 5.68° |
| F X 60 | 0.19801258 | 5.82° |
| G X 130 | 0.20590774 | 5.91° |
| H X 65 | 0.21535373 | 6.18° |
| I X 60 | 0.21662821 | 6.22° |
7V 10/21 geodesic dome chord factors |
||
| 455 3-sided faces | ||
| A x 30 | 0.13774 | 3.95° |
| B x 60 | 0.15197 | 4.36° |
| C x 30 | 0.15664 | 4.49° |
| D x 30 | 0.16154 | 4.63° |
| E x 60 | 0.16480 | 4.73° |
| F x 30 | 0.17066 | 4.90° |
| G x 60 | 0.17098 | 4.90° |
| H x 60 | 0.17132 | 4.91° |
| I x 50 | 0.17353 | 4.98° |
| J x 70 | 0.17585 | 5.04° |
| K x 50 | 0.18155 | 5.21° |
| L x 30 | 0.18161 | 5.21° |
| M x 50 | 0.18237 | 5.23° |
| N x 60 | 0.18548 | 5.32° |
| O x 30 | 0.1879 | 5.39° |
8V geodesic dome chord factors |
||
| 640 3-sided faces | ||
| A x 30 | 0.11946 | 3.42° |
| B x 60 | 0.13033 | 3.74° |
| C x 30 | 0.13424 | 3.85° |
| D x 30 | 0.14018 | 4.02° |
| E x 60 | 0.14056 | 4.03° |
| F x 60 | 0.14548 | 4.17° |
| G x 30 | 0.14628 | 4.19° |
| H x 60 | 0.14803 | 4.24° |
| I x 60 | 0.14862 | 4.26° |
| J x 60 | 0.15267 | 4.38° |
| K x 70 | 0.15296 | 4.39° |
| L x 30 | 0.15315 | 4.39° |
| M x 60 | 0.15477 | 4.44° |
| N x 90 | 0.15636 | 4.48° |
| O x 60 | 0.16033 | 4.60° |
| P x 30 | 0.16036 | 4.60° |
| Q x 70 | 0.16088 | 4.61° |
| R x 60 | 0.16300 | 4.67° |
| S x 30 | 0.16465 | 4.72° |
If you are looking for an advanced explanation of chord factors, bend angles and varying truncations, simplydifferently.org has an extensive and impressive information site on geodesic domes and other structures.
