Question on Calculating Lot Size on Non-broker Gold Pairs

Hi guys,

Can someone who really knows what they're talking about please answer this question. I'm looking for the math formula here. I'd like to make an excel spreadsheet for this..

I don't have XAU/GBP , XAU/EUR, XAU/CAD in my chart but I'd like to trade them. So for a XAU/GBP Long for example, I can Buy XAU/USD and Sell XAU/GBP. My question is, how can I calculate the exact lot size for each currency so that it's even. (If I'm buying 1 lot of XAU/USD and selling 1 lot of GBP/USD its not exactly the same as selling 2 lots of XAU/GBP..)

Math isn't my specialty, looking forward to the answer.

PS. The title is not correct, a better title would have been: Question on Calculating Lot Size on Non-broker Gold Pairs - or something to that effect. lol

ok so let me first put down rates i will use

GBPUSD is roughly 1.47 at the moment
XAUUSD is roughly 1290
(1/1.47) = 0.6802721088

This means Shorting one GBP gives you about 68
Therefore every $1k we long in gold, we must short roughly 680
However this is a problem because we aren't trading whole lots so we must multiply until we are close enough to a micro lot.
The rate in this case would be 878.81632647 for XAUGBP so to get to close to a whole lot we must trade multiply position size by 8x

878.81632647*8 = 7 micro lots short the GBPUSD and long seven ounces of XAUUSD

You now are hedged all but $30