I forget why I made this originally but it might come in handy. 12 and 15 fps in italics.
24 fps in fractions of a second
1 = 0.042
2 = 0.083
3 = 0.125
4 = 0.167
5 = 0.208
6 = 0.250
7 = 0.292
8 = 0.333
9 = 0.375
10 = 0.417
11 = 0.458
12 = 0.500
13 = 0.542
14 = 0.583
15 = 0.625
16 = 0.667
17 = 0.708
18 = 0.750
19 = 0.792
20 = 0.833
21 = 0.875
22 = 0.917
23 = 0.958
24 = 1.000
30 fps in fractions of a second
1 = 0.033
2 = 0.067
3 = 0.100
4 = 0.133
5 = 0.167
6 = 0.200
7 = 0.233
8 = 0.267
9 = 0.300
10 = 0.333
11 = 0.367
12 = 0.400
13 = 0.433
14 = 0.467
15 = 0.500
16 = 0.533
17 = 0.567
18 = 0.600
19 = 0.633
20 = 0.667
21 = 0.700
22 = 0.733
23 = 0.767
24 = 0.800
25 = 0.833
26 = 0.867
27 = 0.900
28 = 0.933
29 = 0.967
30 = 1.000