I am trying to calculate individual predicted probabilities from a logistic regression model with SPSS (to describe how a individual probability could be calculated from my model in an article). I was looking for a formula how the predicted probabilities in SPSS are calculated (automatically when you check "save predicted probabilities"). I've found this video https://www.youtube.com/watch?v=6jj4muvWDgs , which explains quite clearly how the probabilities are calculated in SPSS: 1st step - predicted_logit calculation; 2nd step - predicted probability calculation. This approach works for me as well if I go this way, but in other sources, i.e. here http://www.pmean.com/13/predicted.html the probabilities are calculated differently and yield different individual probabilities.

Therefore my question: is the approach described in the first video correct, and if it is, is it possible to combine the two steps into one relatively simple equation to use in an article?

Thanks in advance!