How to compare POWER of cordless drilla

[xyz321]

Hi

How is the power (which I presume decides how easy is it to drill holes) for cordless drills measured. I realise different manufacturer have different type of materials inside the drill and battery capacity decides how long will it last. but does a 18v drill from makita have same power an 18v from dewalt. Is there a figure(joules or something like) which indicates power and I can use it to compare.

Thanks

 

[foxhole]

A quide.
http://www.dewalt.com/featured-articles/power-tools-what-does-torque-rating-really-mean.aspx

 

[foxhole]

edit

 

[big-all]

as an aside
ignore torque numbers on the clutch ring these do no more than allow the drive to stop at a predetermined level so have no relation to the actual power output

smaller machines will tend to punch above there weight by being lower geared [progress slower]