I've been meaning to publish this more widely since I created it some time ago.

Basically, I took jsid's spreadsheet and made it so that you have to specify how many years you want to sign the contract for, then you are presented with a single set of figures to use - I did it because I was forever copying the wrong column of figures.

You should take a local copy before using it.

Please let me know if there are issues with the file.

https://drive.google.com/file/d/1eAd3MWADh3ONRYddSUJfAFNdwNMqPMkB/view?ths=true