Subnet & CIDR Calculator

Enter any IP address and prefix length. Get network info, host ranges, binary breakdown, and a plain-English explanation of what the mask actually means.

IP Address / Prefix

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Network Address

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Broadcast Address

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Subnet Mask

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Wildcard Mask

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First Usable Host

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Last Usable Host

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Usable Hosts

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IP Class

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Binary breakdown — ■ network bits ■ host bits

// why this mask

CIDR Quick Reference

Prefix	Subnet Mask	Usable Hosts	Networks in Class C	Common Use