You can use SPSS -AMOS text output command to check you SEM model fit indices.
I believe there is no any particular device like SEM fit calculator. Every Software (wherever you are running your model, e.g AMOS, SmartPLS, R etc...) gives you all these statistical measures(fit indices) in it's output/result file.
Thank you so much indeed for the response. Can I know your email id. I can explain more. I wish you a wonderful day Best Regards Nishad. My Email : [email protected].