Reply by HorizontalMike

Everyone makes good points about the ability to use “smaller” wire sizes when running 240v. That is true, but for the small difference in wire prices consider running 10-3 inside your shop.

Here is what I used from HD. The best part of this is that it is an “armored cable” so you do not need to run conduit. NOTE—This is NOT a burial type cable. Interior only.

AFC Cable Systems 125 ft. 10/3 Gauge BX/AC-90 Cable
Model # 1408N32-00
Internet # 202286692
Store SKU # 282805
$136.00 /EA-Each

http://www.homedepot.com/Electrical-Wire-Electrical-Wiring/h_d1/N-5yc1vZbm6mZ1z0zud2/R-202286692/h_d2/ProductDisplay?catalogId=10053&langId=-1&storeId=10051#.UIAPf4ZP_QU

FOR BURIAL USE TO THE SHOP:
I do not know how far you need to run service. That will dictate how large a cable to use. You will need to find out the requirements for the distance you will be installing.

FWIW, running service to my garage (100amp service) I ran #00 twisted wire w/ground overhead. That was overkill on my part, so check locally for what you need to be looking at.

IF #10 is adequate for your service to your free standing shop/garage:

Southwire 250 ft. 10-2 UF-B W/G Cable
Model # 13056755
Internet # 202316282
Store SKU # 269077
$224.00 /EA-Each

It can also be used for outbuildings such as garages and barns. UF-B feeds from a distribution point in an existing building. UF-B has a heat capacity of 90* C and is rated at 600 volts. UL Listed and CSA Certified.

http://www.homedepot.com/Electrical-Wire-Electrical-Wiring-Service-Entrance-Wire/h_d1/N-5yc1vZbm3u/R-202316282/h_d2/ProductDisplay?catalogId=10053&langId=-1&storeId=10051#.UIAZvIZP_QU

-- HorizontalMike -- "Woodpeckers understand..."