The Bible does not specifically mention Adam’s height, but given what we know of anthropology and genetic development, there is a good estimate of how tall Adam would have been. Based on Biblical and anthropological accounts, it is likely that Adam was around 5’6”-5’8” tall.
The earliest humans, Homo sapiens, were believed to have been around 5’1”-5’7” depending on their gender and geographic region. Adam would have been no taller than this since his parts of his DNA are believed to originate from Homo sapiens. So, Adam could have been slightly taller, but likely no taller than 5’8”.
Adam’s son, Cain, was believed to be six feet tall. This means that he would have been taller than his father, Adam. It is likely that this was an evolutionary trait, as humans have been growing taller over time.
To get an even better idea of the differences between the height of Adam and his son Cain, it’s worth mentioning that Adam was also thought to have lived 930 years while Cain lived 770 years. This means that Adam had more time to have grown taller than Cain.
Overall, the Bible does not give us an exact figure for Adam’s height and so if we are to make an estimation, it is likely that Adam was between 5’6”-5’8” tall.