I am an American Airlines guy that's where all my miles are, but I can't bring them over from Capital One Venture Card. So I was looking at British Airways instead. It's 1,000 points to 1,000 avios. Being that I get points on my Capital One Venture Card, I can't seem to figure out in my head if it's better to use the Capital One Venture Card to get the double points or to use a Barclays card which gives me $1 per mile on American. Is this some kind of calculation that I can use for all this stuff thank you

Welcome to FT, Gorelow!
I have no experience with the Capital One Venture Card, but I doubt that it is to your advantage to split your miles/avios between AA and BA.

If you get avios what would you use them for?
Avois currency is used by BA, IB, IE, QR & AY. Subject to t&c's avios can be moved from 1 airline ffp to another airline ffp.
Frequent flyer miles/avios/points are not 1:1 to earn or burn(awards), even if credit cards transfer at the same rate.

FT forum https://www.flyertalk.com/forum/capi...rds-miles-778/

Yes I noticed it was $35,000 obvious to do the same thing you can do for $30,000 American but I can't get a double mileage on any credit card that I have except for this one towards British Airways

Gorelow , suggest that you thoroughly familiarize yourself with the various FFPs which use Avios as their "currency," and then try to determine whether you would get more value with Avios compared to using your Capital One "miles" to purchase cash tickets from the Capital One travel portal.

In the most recent thread on AA miles valuation, there are many opinions, but 1.5 CPM is a number that most seem to able to accept (i e. if there was a marketplace, bids and asks would converge near that number).

If you accept this premise, any card that provides more than $0.015 per dollar is better than Barclays or Citi for everyday spending ($0.02 cash back is pretty easy to snag).... unless the status boost is important.
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Agree with this analysis and the 1.5 cpp valuation on AA. OP I can give you an idea of how I think about this -

For AA miles, I get a lot more value on certain long-haul J redemptions as well as last-minute domestic economy bookings if saver space opens up, but in general it's around 1.5 cpp, e.g. summer and winter travel. Note that in my calculations, I tend to measure cpp as price I'd pay (including alternative airlines, even the likes of Frontier and Spirit if no bags) divided by the points redeemed. Others use the AA fare divided by the points redeemed and so the 1.5 may fluctuate.

For Avios, I exclusively use them on two things - long haul J on Qatar because I like the product and convenience for my parents and last-minute domestic bookings when AA miles are dynamically priced (avios are distance based and fixed). These two give me greater than 1.5 cpp in value but only up to a certain point and becomes useless beyond that.