Subnet calculator
🔒 Runs locally in your browser. Nothing you enter is uploaded.
How to use it
- Enter an address like 192.168.10.37/26.
- Read the network, mask, wildcard and host range.
- Use the wildcard mask in firewall or router ACLs.
Frequently asked questions
How many hosts in a /24?
254 usable hosts (256 addresses minus network and broadcast).
What are private IP ranges?
10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 (RFC 1918).
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