Now with single winner elections the proportion of wasted votes is always going to be over 50%, now I would like to preface that I know it's not always necessarily a bad metric if someone's popular and wins by 70% of the vote to 30% well that's 40% of the votes surplus, not helping the winner win so count as wasted. But of course that wasn't the case.

Now if the US election had been fought under under national popular vote the proportion of wasted votes would have been 51.93% add IRV to that (and it should be) that would have gone down even lower, You could probably figure out roughly what that would likely be if any second preference polling was done to third party voters. Also under IRV I would also expect the number of votes for third parties to go up significantly, that system allows people to vote with their heart knowing they're not sending it into the abyss.

Anyway with the electoral college it become a bit trickier to figure out what the proportion of wasted votes was at the last presidential election It would be I was wondering if anybody had tools to be able to work this out quicker than me.
The wasted votes in the last presidential election would be all votes for anyone Trump included in every state Hillary won, so that would the entire state of New York and California for a start. Add to that all votes not for Trump in every State Trump won and finally add surplussed vote for Trump in the states Trump won. That would be the total tally of wasted votes in 2016.