When traveling from LA to Heathrow, what is the average number of miles to upgrade to business on BA?

Yah, I'm going from LA to London on BA this July. I want to upgrade, have maybe enough miles. I would like to upgrade to something a little nicer than economy. What is the average amount of miles I would need? Also, could I use miles from American Airlines?

On American Airlines a one-way upgrade to Europe from N. America is 25,000 miles plus $300. Although BA is a partner with American Airlines in the One World Alliance, you cannot use American miles to upgrade a BA flight. You should check AAdvantage website, it should give you information you need.
Most always, you need to have miles from the airline you're flying on to be able to upgrade, although you can use miles from partner airlines to get award travel (not upgrades).

Upgrading is not that easy..
Usually, it takes approximately 40,000 miles, but the problem is that in most of the cases, it is not available for upgrade (they ave allocated spots for mileage use, and in most cases it all taken)
You really need to plan long time a head if you want to upgrade.