Very firm, well compared to the medium firm mattress. I had purchased that first but it was too soft. I didn’t realize how firm my boyfriend and I liked a mattress so we purchased this next. The medium mattress similar to this will now be the perfect guest mattress. With two people there isn’t too much movement when one person moves. The medium mattress drove us both nuts. I highly recommend the firm mattress shown here. I thought it a bit odd that both the mattress and boxspring came in the same box. That made it awkward to get inside, but hey who said moving in furniture would be easy!