# Finding the simple formula for like vs dislike ratio percentage

I have a like button and a dislike button. I want to quickly display in a percentage format how much people like it, -100% being everyone dislikes and 100% being everyone likes.

What would be the math forumula to find this percentage.

Say 100 people like it and 50 people hate it.

Would it be something like

100 + 50 / 2 ?

Thanks! Jeff

• How about #likes/total ? So your case would be $\frac {100}{150}=66.66\dots \%$ – lulu Aug 21 '18 at 20:08
• @lulu: that gives $0$ when everyone dislikes, not $-100\%$ – Ross Millikan Aug 21 '18 at 20:14
• @RossMillikan Ah, true. – lulu Aug 21 '18 at 20:17

You can use $$\frac {likes-dislikes}{likes+dislikes}$$
• In other words, the average value of a vote, where a like is worth $1$ and a dislike is worth $-1$. – Jack M Aug 21 '18 at 20:24