1400TC 6-Piece Sheet Set

What are the actual specifications on the thread count? Is this 1400 per sq. inch? A lot of knock offs claim a high TC but it’s not based on the square inch and markets the product as higher in quality than it actually is. Just wondering if anybody knows for these particular sheets.

It’s a true 1400 thread count of a polyester/cotton blend.

They say 1400 per square inch. I bought two sets and they feel a bit rough to me.