If the 13C-shifts of the unsubstituted alkane are not known, they can be calculated by
using the Grant-Paul-Rules
The individual increments are
In addition a steric correction factor 
has to be taken into account.
| Ci (observed C-atom) | -CH3 | -CH2- | -CH- | -C- | |
| primary | -CH3 |
0
|
0
|
-1.1
|
-3.4
|
| secondary | -CH2- |
0
|
0
|
-2.5
|
-7.5
|
| tertiary | -CH- |
0
|
-3.7
|
-9.5
|
(-15.0) |
| quartenary | -C- |
-1.5
|
-8.4
|
(-15.0)
|
(-25.0) |
The chemical shift can be calculated based on the following equation and increments given in the table below:
| Substituent | alpha | beta | gamma | delta |
| -C=C- | 20.0 | 6.9 | -2.1 | 0.4 |
| -CC- (alkyne) | 4.4 | 5.6 | -3.4 | -0.6 |
| -C6H5 | 22.1 | 9.3 | -2.6 | 0.3 |
| -CHO | 29.9 | -0.6 | -2.7 | 0 |
| -COR | 22.5 | 3.0 | -3.0 | 0 |
| -COOH | 20.1 | 2.0 | -2.8 | 0 |
| -COOR | 22.6 | 2.0 | -2.8 | 0 |
| -CONR2 | 22.0 | 2.6 | -3.2 | -0.4 |
| -COCl | 33.1 | 2.3 | -3.6 | 0 |
| -CN (nitrile) | 3.1 | 2.4 | -3.3 | -0.5 |
| -OH | 49.0 | 10.1 | -6.2 | 0 |
| -OR | 58.0 | 7.2 | -5.8 | 0 |
| -OCOR | 54.0 | 6.5 | -6.0 | 0 |
| -NR2 | 28.3 | 11.3 | -5.1 | 0 |
| -NR3+ | 30.7 | 5.4 | -7.2 | -1.4 |
| -NO2 | 61.6 | 3.1 | -4.6 | -1.0 |
| -SH | 10.6 | 11.4 | -3.6 | -0.4 |
| - SCH3 | 20.4 | 6.2 | -2.7 | 0 |
| -F | 70.1 | 7.8 | -6.8 | 0 |
| -Cl | 31.0 | 10.0 | -5.1 | -0.5 |
| -Br | 18.9 | 11.0 | -3.8 | -0.7 |
| -I | -7.2 | 10.9 | -1.5 | -0.9 |
Example: 1-Hexyne
