- 1tube

1/8 - 0.125
Kwart tube
3/8 - 0.375
Halve tube
5/8 - 0.625
Driekwart
7/8 - 0.875
1 tube

+ 1tube

1t 1/8 - 1.125
Tube + kwart
1t 3/8 - 1.375
Tube + half
1t 5/8 - 1.625
Tube + 3/4
1t 7/8 - 1.875
2t - 2