Free tool · Networking
CIDR subnet calculator
Type an IPv4 address, or paste a block like 10.0.0.0/16, and get the subnet mask, wildcard mask, network and broadcast addresses, usable host range and host count.
IPv4 CIDR subnet calculator
| CIDR block | 192.168.1.0/24 |
|---|---|
| Subnet mask | 255.255.255.0 |
| Wildcard mask | 0.0.0.255 |
| Network address | 192.168.1.0 |
| Broadcast address | 192.168.1.255 |
| Usable host range | 192.168.1.1 – 192.168.1.254 |
| Total addresses | 256 |
| Usable hosts | 254 |
| Address type | Private (RFC 1918) |
Quick reference
/24: 255.255.255.0, 256 addresses, 254 usable hosts./26: 255.255.255.192, 64 addresses, 62 usable./28: 255.255.255.240, 16 addresses, 14 usable./30: 255.255.255.252, 4 addresses, 2 usable./31: 2 addresses, both usable on point-to-point links (RFC 3021)./32: a single host address.
Tips for cloud VPCs
- Keep VPC ranges inside the private blocks 10.0.0.0/8, 172.16.0.0/12 or 192.168.0.0/16.
- Avoid ranges that overlap your office or home network if you plan to connect them with a VPN.
- Cloud providers can reserve extra addresses in each subnet (AWS reserves five), so size subnets with some slack.