How many /28 IPv4 subnets can be created within a /24 IPv4 prefix?

A /24 IPv4 prefix provides 256 IP addresses, which is the number of addresses in one octet (2^8). A /28 subnet has 16 IP addresses (2^4). To calculate how many /28 subnets can fit into a /24 prefix, divide the total number of addresses in the /24 prefix by the number of addresses in a /28 subnet: 256 / 16 = 16. However, since each subnet has network and broadcast addresses that cannot be used for hosts, the actual number of usable subnets is less. In practice, you can create 16 subnets, each with 14 usable IP addresses for hosts.

References:

Subnet Cheat Sheet

IP Subnet Calculator