In my opinion, to make an informed decision, you need to review several key pieces of information:

1) how much do you plan to put towards your balance each month? (the minimum balance due, a fixed amount monthly, or the minimum payment plus some additional extra payments at fixed schedules, or the minimum payment plus some additional extra payments at random times?)

2) Who is the current card issuer where you carry the balance. Banks will not let you complete a balance transfer from one of their cards to another card they also maintain, so for instance if your current balance is on a Chase card then that precludes you from completing a balance transfer to any other Chase card. It works the same way with all banks, Bank of America, Citi, Wells Fargo, Capital One, Barclays, etc. (This doesn't mean that you can complete manufactured spend on another card issued by the same issuer as your current card (Chase to Chase for instance) with a 0% purchase APR and use that to pay down your card with a balance. However, this does involve more work, time, gas, and risk.

Once you understand your expected payment schedule and verify that the cards you have promotional offers on are not issued by the same bank as the card you are trying to payoff, then you can use the calculators to make a more informed decision. However, remember it is important to make an apples to apples comparison to make the correct informed decision. As such, if for example you are comparing a payment of $100 monthly on the 19% APR card with the 0% card with 3% transaction fee, it is important to make sure that the payments are equal ($100.00). Otherwise, the information presented will not provide a proper means for comparison.