Chroma-Subsampling: How to properly calculate the data-rate I am having a hard time understanding how to calculate the data rate when leveraging chroma-subsampling in e.g. a Y'UV image:

I have the following examples for a calculation: 

Image resolution: 352*288 
Frequency: 25 fps

For (4:4:4) the example calculation goes as follows:

(352px * 288px) * 3 color channels * 25 fps * 8 bit = 60 825 600 bit/s

So far so good. 

But now comes (4:2:0):

(352px*288px) * 1.5 color channels * 25 * 8 = 30 412 800 bit/s

Now, trying to transfer this example to e.g. (4:1:1) I realized I am not sure whether I have a correct understanding how the ratio of 1.5 color channels is being calculated. 

My first guess for the calculation was in case of (4:2:0): 
2/4*3=1.5 color channels
Likewise for (4:1:1) I would calculate the ratio for the color channels as: 

1/4*3=0.75 color channels

But I am simply not sure whether this would be the correct way to go.
As an alternative, I was thinking along following lines: 

color channels (4:1:1): 1 Y' + 1/4 UV = 1.25 color channels

Now which would be the correct way of doing this properly?
Here is a reference to know the difference. I am adding the essential diagram as well: 

  

what you realize is that 4:1:1 has full vertical resolution but 1/4 of Horizontal resolution, where as 4:2:0 has half of vertical as well half horizontal resolution.

However, overall, 4:2:0 and 4:1:1 will have the same number of samples and hence the same bit rate.