There're a few calculators on line to help figure out what the new torque will be. I didn't see a darn thing other than the info.

But the quick and easy solution to the problem is... turn the wrench so that it's at a right angle to the torque wrench. There's still a difference, but it's a small one.

From

http://norbar.com/calculators/torque-wrench-extension-calculator.aspxWhen you put an extension on a torque wrench, like a crow foot or a dog bone, the torque applied to the fastener increases, since the lever arm increases. Use the calculator below to find what value you should set into the wrench to achieve the required fastener torque You must have Java enabled on your web browser, then you should see a calculator appear below.

While we have done our best to test this program, we cannot be responsible for errors or damages that result from its use. You must verify that the values obtained from the calculator are accurate before using them in any critical application.

This applet is based on the formula:

M1 = M2 x L1 / L2

Where:

M1 is the torque setting of the wrench.

M2 is the actual torque applied to the nut

L1 is the normal length of the wrench

L2 is the extended length of the wrench