Originally Posted by

**Mike Tuchscherer**
I did the same thing -- I correlated RPE and velocity. I found that RPE is fairly predictable if you know your velocity at 1RM. So if you are particularly grindy on one lift, then the RPE-velocity correlation would be different.

Anyway... here's the equation:

RPE = ((Vmin/[V@1RM])-6)/(-0.5)

Vmin is the velocity (average, not peak) of the slowest rep in the set. This is typically the last rep, but may not be.

V@1RM is the velocity of a 1RM attempt in that lift.

The most accurate way to get v@1RM is to do an actual 1RM and measure it. But you can estimate it too. Just do a set (or a few sets) and rate your subjective RPE.

RPE = Subjective RPE

Vmin = velocity of the slowest rep in the set

V@1RM = Vmin / (RPE * -0.6 + 7.0333)

Doing this more than once and taking a reasonable average would probably be better than a single trial. And the more accurate you can be with your RPE the better. So few reps, higher RPE is going to be more accurate than lower reps and lower RPE.