Once you have your number, simply divide it by the current stock price, and there it is -- your forward dividend. So, if your stock is paying $0.50 this quarter, you'd be getting $2 per year if all remains stable; assuming today's price is $50, that's a 4% forward dividend yield. Here's the formula and result:
Annualized dividend / stock price = forward dividend yield
$2 / $50 = 4%
Of course, there are also analysts out there who do a much more thorough analysis to come up with predictions for forward dividend yields that may be helpful to track as you shop for your next stock pick. These guys also don't have an infallible Magic 8-Ball, but they do have loads of experience to help them make a very informed guess.
Forward dividend yield vs. trailing dividend yield
There are many ways to look at dividend yield, but the most common are forward yield and trailing yield. These may turn out to be the same, but the two terms look at very different things.