the answer is more complex than that. It depends on multiple factors including including but not limited to:
What type of WLAN (Open, WPA2-PSK, WPA2-Enterprise etc)
What type of encryption will be used (AES-CCMP or TKIP) if any
Standalone or controller based
Also, concurrent user support is quoted on associations not traffic passing clients so the max number of supported devices will always be greater than the max number of clients that can be associated and passing traffic over any given period.