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    CIDR Calculator

    Pick a prefix to see its mask, capacity and how it divides into smaller subnets — plus a full reference table from /8 to /32.

    Subnet mask
    255.255.255.0
    Total addresses
    256
    Usable hosts
    254
    Host bits
    8
    Split result
    4 × /26
    Hosts per subnet
    62

    CIDR prefix reference table

    IPv4 CIDR prefix reference
    PrefixSubnet maskTotal addressesUsable hosts
    /8255.0.0.016,777,21616,777,214
    /9255.128.0.08,388,6088,388,606
    /10255.192.0.04,194,3044,194,302
    /11255.224.0.02,097,1522,097,150
    /12255.240.0.01,048,5761,048,574
    /13255.248.0.0524,288524,286
    /14255.252.0.0262,144262,142
    /15255.254.0.0131,072131,070
    /16255.255.0.065,53665,534
    /17255.255.128.032,76832,766
    /18255.255.192.016,38416,382
    /19255.255.224.08,1928,190
    /20255.255.240.04,0964,094
    /21255.255.248.02,0482,046
    /22255.255.252.01,0241,022
    /23255.255.254.0512510
    /24255.255.255.0256254
    /25255.255.255.128128126
    /26255.255.255.1926462
    /27255.255.255.2243230
    /28255.255.255.2401614
    /29255.255.255.24886
    /30255.255.255.25242
    /31255.255.255.25422
    /32255.255.255.25511

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