We recommend the FBA fee calculator that Seller Central provides, as that one should always be the most up to date and the most accurate. The information is taken directly from their own database so there is less chance of any issues. You can use the other calculators at a glance as they can be quick and convenient, but it is always run it through the FBA Fee Calculator prior to purchasing.
Is the Helium 10 calculator the same as the Amazon profit calculator?
What revenue calcultor should I use?