◧ DEVELOPER Updated July 25, 2026

IP Subnet Calculator

Drop in an IPv4 address and prefix to get the whole subnet breakdown.

IPv4 address
Prefix length (CIDR)
Result
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How it works

The address and prefix are converted to 32-bit integers; masking gives the network and broadcast addresses, and the remaining host bits determine the usable range and host count.

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Frequently asked questions

Why are two addresses unusable?

The first address identifies the network and the last is the broadcast address, so a /24 has 254 usable hosts, not 256.

What does /24 mean?

It means the first 24 bits are the network portion, equivalent to a 255.255.255.0 subnet mask.

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