Network & DevOps ToolkitSubnet / CIDR Calculator
Compute network, broadcast, mask, host range and counts for any IPv4 CIDR.
Enter an IPv4 address and drag the prefix — every derived value updates instantly.
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How many hosts does a /24 hold?
A /24 has 256 addresses, of which 254 are usable hosts (the network and broadcast addresses are reserved).
What is the difference between a network and a broadcast address?
The network address is the first address in the block (all host bits 0) and identifies the subnet; the broadcast address is the last (all host bits 1) and reaches every host on the subnet.
How do I split a block into smaller subnets?
Increase the prefix length. Each extra bit halves the block — a /24 splits into two /25s, four /26s, and so on.
Related tools
- Number Base Converter — turn octets and masks into binary/hex.
- DNS Lookup — find the addresses a hostname resolves to.
- Data Size Converter — size the traffic a subnet carries.
🔐 Private by design: every tool runs in your browser. DNS lookups go straight to Cloudflare's DoH resolver (1.1.1.1); nothing else is sent to any server, and nothing is logged.