I do a walk/jog combo on a treadmill.
The treadmill we have shows laps of 1/4 mile. I walk the first lap, then jog 2 laps, walk 1 jog 2, walk 1, jog 2 and then slow walk about a half lap to cool down.
So, altogether, I walk/jog 2 1/4 miles.
I have really become addicted to it and get very grumpy if I miss a day (like I did today!)