Subnet Calculator
Calculate IP subnets with CIDR notation. Get network addresses, broadcast addresses, host ranges, and visual subnet breakdowns.
Network Configuration
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Quick Examples:
Common Subnet Masks
| CIDR | Subnet Mask | Usable Hosts | Description |
|---|---|---|---|
| /8 | 255.0.0.0 | 16,777,214 | Class A |
| /16 | 255.255.0.0 | 65,534 | Class B |
| /24 | 255.255.255.0 | 254 | Class C |
| /25 | 255.255.255.128 | 126 | 1/2 Class C |
| /26 | 255.255.255.192 | 62 | 1/4 Class C |
| /27 | 255.255.255.224 | 30 | 1/8 Class C |
| /28 | 255.255.255.240 | 14 | 1/16 Class C |
| /29 | 255.255.255.248 | 6 | 1/32 Class C |
| /30 | 255.255.255.252 | 2 | Point-to-Point |
| /31 | 255.255.255.254 | 2 | Point-to-Point (RFC 3021) |
| /32 | 255.255.255.255 | 1 | Host Route |
About this tool
Calculates network address, broadcast address, usable host range, and subnet mask from CIDR notation or an IP/mask pair, with a visual breakdown of the subnet.
When you’d use it
- Working out how many usable hosts a /27 actually gives you before carving up a VLAN.
- Checking whether two proposed subnets overlap before assigning them.
Frequently asked questions
- Does it handle IPv6?
- No, this calculator is IPv4 only.
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