Subnet Calculator
IPv4 CIDR, host range and masks
IP Address
You can also paste 192.168.0.10/24
Network
192.168.0.0/24
Usable hosts 254
Network address192.168.0.0
Broadcast address192.168.0.255
Usable host range192.168.0.1 ~ 192.168.0.254
Subnet mask255.255.255.0
Wildcard mask0.0.0.255
Class · typeC
IP (binary)
Mask (binary)
CIDR Subnet Chart (/16 to /32)
| CIDR | Subnet mask | Addresses | Usable hosts |
|---|---|---|---|
| /16 | 255.255.0.0 | 65,536 | 65,534 |
| /17 | 255.255.128.0 | 32,768 | 32,766 |
| /18 | 255.255.192.0 | 16,384 | 16,382 |
| /19 | 255.255.224.0 | 8,192 | 8,190 |
| /20 | 255.255.240.0 | 4,096 | 4,094 |
| /21 | 255.255.248.0 | 2,048 | 2,046 |
| /22 | 255.255.252.0 | 1,024 | 1,022 |
| /23 | 255.255.254.0 | 512 | 510 |
| /24 | 255.255.255.0 | 256 | 254 |
| /25 | 255.255.255.128 | 128 | 126 |
| /26 | 255.255.255.192 | 64 | 62 |
| /27 | 255.255.255.224 | 32 | 30 |
| /28 | 255.255.255.240 | 16 | 14 |
| /29 | 255.255.255.248 | 8 | 6 |
| /30 | 255.255.255.252 | 4 | 2 |
| /31 | 255.255.255.254 | 2 | 2 |
| /32 | 255.255.255.255 | 1 | 1 |
Usable hosts exclude the network and broadcast addresses. A /31 uses both addresses for point-to-point links (RFC 3021); a /32 is a single host.
Private & Special Ranges
| Range | Use |
|---|---|
| 10.0.0.0/8 | Private (large networks) |
| 172.16.0.0/12 | Private |
| 192.168.0.0/16 | Private (home and office routers) |
| 100.64.0.0/10 | Carrier-grade NAT |
| 127.0.0.0/8 | Loopback |
| 169.254.0.0/16 | Link-local (no DHCP) |
Formulas & Sources
- Network = IP AND mask · broadcast = network OR wildcard
- Private ranges: RFC 1918 · CGNAT: RFC 6598 · /31: RFC 3021 · IPv4 only
Last reviewed: 2026-10-19
FAQ
How many hosts are in a /24?
A /24 (255.255.255.0) has 256 addresses, of which 254 are usable after removing the network and broadcast addresses.
How do I get the subnet mask from CIDR?
Set that many leading bits to 1. /26 means 26 ones: 255.255.255.192.
What are the network and broadcast addresses?
AND the IP with the mask to get the network address; set all host bits to 1 for the broadcast address. Neither can be assigned to a device.
Which IP ranges are private?
10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 (RFC 1918). 100.64.0.0/10 is carrier-grade NAT.
What is a wildcard mask?
The inverse of the subnet mask, used in router ACLs and OSPF to match address ranges.