/28 Subnet Mask (255.255.255.240)
| Prefix | /28 |
|---|---|
| Subnet mask | 255.255.255.240 |
| Wildcard mask | 0.0.0.15 |
| Binary mask | 11111111.11111111.11111111.11110000 |
| Total addresses | 16 |
| Usable hosts | 14 |
| Host bits | 4 |
| Subnets of /28 in a /24 | 16 |
| Block size | 16 addresses (subnets start every 16 in the last octet) |
e.g. 10.0.0.5/22 or 10.0.0.5 255.255.252.0
| Network address | 192.168.1.0 | |
|---|---|---|
| Broadcast address | 192.168.1.15 | |
| First usable host | 192.168.1.1 | |
| Last usable host | 192.168.1.14 | |
| Total addresses | 16 | |
| Usable hosts | 14 | |
| Subnet mask | 255.255.255.240 | |
| Wildcard mask | 0.0.0.15 | |
| CIDR notation | 192.168.1.0/28 | |
| IP class | Class C (legacy) | |
| Address type | Private (RFC 1918) | |
| IP address (binary) | 11000000.10101000.00000001.00000000 | |
| Subnet mask (binary) | 11111111.11111111.11111111.11110000 |
■ network bits ■ host bits
| Requested hosts | CIDR | First host | Last host | Broadcast | Usable hosts |
|---|
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What is a /28 subnet?
A /28 subnet uses the first 28 bits of an IPv4 address for the network and leaves 4 bits for hosts. Its subnet mask is 255.255.255.240, and it contains 2⁴ = 16 addresses, of which 14 can be assigned to devices. Typical use: Small segments: DMZs, management networks, printer or camera VLANs. Use the subnet calculator above to check any /28 network.
/28 subnet example
For 192.168.1.0/28: network address 192.168.1.0, usable hosts 192.168.1.1 – 192.168.1.14, broadcast address 192.168.1.15, wildcard mask 0.0.0.15.
/28 networks in 192.168.1.0/24
A /24 holds 16 /28 networks:
- 192.168.1.0/28
- 192.168.1.16/28
- 192.168.1.32/28
- 192.168.1.48/28
- 192.168.1.64/28
- 192.168.1.80/28
- 192.168.1.96/28
- 192.168.1.112/28
- 192.168.1.128/28
- 192.168.1.144/28
- 192.168.1.160/28
- 192.168.1.176/28
- 192.168.1.192/28
- 192.168.1.208/28
- 192.168.1.224/28
- 192.168.1.240/28
Frequently asked questions
How many usable IPs are in a /28?
14. The block has 16 addresses; the first is the network address and the last is the broadcast address.
What is the subnet mask for /28?
255.255.255.240, or 11111111.11111111.11111111.11110000 in binary.
How many /28 subnets are in a /24?
16 (2⁴), because a /28 uses 4 more network bits than a /24.
What is the difference between /28 and /27?
A /27 (255.255.255.224) is twice as large: 32 addresses and 30 usable hosts, spanning two consecutive /28 blocks such as 192.168.1.0–192.168.1.31.