Subnet Calculator

One IPv4 address plus a CIDR — network, broadcast, hosts and range.

FREE TOOL · WORKS OFFLINE · NO SIGN-UP

Results update instantly as you type.

Usable hosts
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Network address
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Broadcast address
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Subnet mask
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Usable host range
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Total addresses
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How to Use This Subnet Calculator

  1. 1.Enter the IPv4 address. Any address inside the subnet works — the calculator finds the network for you.
  2. 2.Set the CIDR prefix. 24 is the classic home and office network; larger numbers mean smaller networks.
  3. 3.Read the network and broadcast. The network is the first address, the broadcast is the last.
  4. 4.Read the usable range. These are the addresses you can actually assign to devices.
  5. 5.Check the host count. Total addresses minus the network and broadcast addresses, except for /31 and /32.

FAQ

What does 192.168.1.0/24 break down to?

For 192.168.1.0/24 the network address is 192.168.1.0, the broadcast address is 192.168.1.255, there are 254 usable hosts, and the usable host range is 192.168.1.1 to 192.168.1.254.

Why are there 254 usable hosts in a /24 and not 256?

A /24 holds 256 addresses, but two are reserved: the network address itself and the broadcast address. Subtracting those two leaves 254 addresses for devices.

What is the difference between the network and broadcast addresses?

The network address identifies the subnet itself, and the broadcast address sends a message to every device on it. Neither one is assigned to a single device in a normal network.

Is this subnet calculator free?

Yes — 100% free, no sign-up, no limits. Everything runs in your browser; none of your numbers are uploaded or saved.

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