IP subnet calculator (CIDR)
For office and industrial networks and device configuration: everything about an IPv4 subnet from a single address.
Result
- Mask
- 255.255.255.0 (/24)
- Wildcard mask
- 0.0.0.255
- Network address
- 192.168.1.0
- Broadcast address
- 192.168.1.255
- First host
- 192.168.1.1
- Last host
- 192.168.1.254
- Addresses in block
- 256
- Address type
- private (RFC 1918)
- Address in hex
- 0xC0A8010A
| Item | binary |
|---|---|
| Address | 11000000.10101000.00000001.00001010 |
| Mask | 11111111.11111111.11111111.00000000 |
| Network | 11000000.10101000.00000001.00000000 |
What /24 means
CIDR notation such as 192.168.1.0/24 says how many leading bits of the address (here 24 of 32) are the network number. The other 8 bits number the devices: 2⁸ = 256 addresses, of which the first is the network address and the last the broadcast address, leaving 254 for hosts.
| Prefix | Mask | Hosts |
|---|---|---|
| /30 | 255.255.255.252 | 2 |
| /29 | 255.255.255.248 | 6 |
| /28 | 255.255.255.240 | 14 |
| /27 | 255.255.255.224 | 30 |
| /26 | 255.255.255.192 | 62 |
| /25 | 255.255.255.128 | 126 |
| /24 | 255.255.255.0 | 254 |
| /23 | 255.255.254.0 | 510 |
| /22 | 255.255.252.0 | 1022 |
| /16 | 255.255.0.0 | 65,534 |
Industrial networks
PLCs, HMIs and fieldbus devices (PROFINET, EtherNet/IP, Modbus TCP) usually get fixed addresses in one subnet. Devices talk directly only within the same subnet; reaching another network needs a gateway (router). The “is the address in the network” check shows straight away whether two devices can see each other without a router.
Common questions
How many hosts does a /24 have?
254: of the 256 addresses, the first is the network address and the last the broadcast address.
What mask is a /26?
255.255.255.192. A /26 has 64 addresses and 62 hosts.