ccj's calculator is not that accurate. It just gives you a general area where your VJ should be.
Every individual is different , your body leverages , bodyfat % , coordination and jumping efficiency are not included in that calculator.
Here's what kellyb says about it:
The basic idea is that for a given squat and bodyweight you SHOULD be able to jump a given height AS LONG AS your movement efficiency in the jump is up to par. If your current squat gives you a vertical jump forecast that is above your actual current jump height you know you need to work on transferring your squat strength into jump explosiveness better, thus you need more actual jump training and perhaps more explosive oriented training. If your VJ is even, or above, the forecasted VJ, you know your jumping efficiency is good, you're transferring your strength into explosiveness well, and should continue driving up your squat.
Note: The calculator works best if you're between 5'6 and 6'0 tall. Shorter folks tend to require slightly heavier squats for a given VJ and taller folks tend to require slightly less.
This calculator is not any scientific miracle , the formula is VJ = 16,75*( squat/bodyweight ). I don't know if that 16,75 is a ratio that worked accurately for ccj or if it is an average of some kind of study.
What i do know is that if you have a detailed log , go back to your data, see what VJ you had for each squat/bw ratio at times and find your own ratio so you can have your own personal calculator.
pc