The number of frames to perform input of a special cancel?

Hi SRK members,

I had a question which has been bugging me for awhile. I tried to find the answer without creating a thread but the newbie guides for frame data and google search results don`t quite explain what I want to know. Please close this thread if this has been answered already or belongs to the SFIV forum.

Question:
When it comes to cancelling normal moves into specials, how many frames do I have to work with to input the special move during the animation of the normal?

Example:
Ryu`s c.MK -> Hadoken

Startup (5 frames) | Active (5 frames) | Recovery (12 Frames) | Total (21 Frames)

Hadoken 13 Frame Startup

So based on this data how many frames do I have to input the motion for Hadoken after performing the c.MK? Do I have to input the special during the Startup+ Active giving me 10 frames to work with? Or can it be cancelled during the recovery meaning I have 21 frames to perform the normal cancel? I hope my question is clear! (if not let me know)

Note: I don`t really have issues doing cancels because of input buffering, but this is more about understanding the system.

Good question. Dont know. Some seem more than others.

Startup (4 frames, 5 frames means the fifth frame is the first active frame) + active frames (5 frames) + hit stop (I think it’s 11 frames but I’m not entirely sure), so 20 frames in total.