Based on this calculator if someone play perfect hands the house edge is 0.35%, however I don't that's what most players would be able to achieve. Human is generally sucks at gambling. Of course I don't have a calculator to pull up that number which is mostly based on my experience and perhaps this article:
The house edge in blackjack is around 0.5% if you use basic strategy.
Of course, that 0.5% can go up or down based on your skill level. Most players are bad enough at blackjack basic strategy to give up another 1.5% or so to the house, making the house edge for the casino 2%.
https://www.gamblingsites.com/blog/the-house-edge-in-blackjack-28277/