Emacs calc can do financial/TVM calculations, too. A useful tutorial by Andrew Hyatt on doing financial calculations [0]; he has wrote many other calc tutorials [1] in the Emacs Google Plus community [2].

[0] Emacs financial calculations: https://plus.google.com/+AndrewHyatt/posts/YdwsbNmZ4NL

[1] Index of Andrew Hyatt's emacs calc tutorials: https://blog.markhepburn.com/2013/12/07/andrew-hyatts-emacs-...

[2] Emacs Google Plus community: https://plus.google.com/communities/114815898697665598016