6 calculators in this category
- IPv4 Subnet Calculator (CIDR)RFC 4632 (CIDR), RFC 950, RFC 1918Give this calculator an IPv4 address and a prefix length and it resolves the address to the block it belongs to: the network…
- Subnet Mask to CIDR Converter CalculatorRFC 4632 (CIDR), RFC 1878Routers, firewalls, cloud consoles and operating systems all describe the same 32-bit value in different notations: /26…
- Hosts per Subnet CalculatorRFC 4632 (CIDR), RFC 3021 (/31 links)Enter a prefix length and this calculator tells you how many addresses the block contains and how many of them you can actually…
- VLSM Subnet Design CalculatorCIDR (RFC 4632) with RFC 3021 /31 linksEnter a parent block and how many hosts each segment needs, and this calculator builds the whole variable-length subnet plan…
- Wildcard Mask Calculator (ACL)Cisco IOS access-list and OSPF network syntaxA wildcard mask is a subnet mask turned inside out: every bit that must match is a 0, and every bit the router should ignore is…
- IPv6 Subnet & Prefix CalculatorRFC 4291 / RFC 5952Give this calculator an IPv6 prefix and a target subnet size and it returns the first and last address in the block, how many…
Which one do you need?
- IPv4 Subnet Calculator (CIDR)
- Enter any IPv4 address and prefix to get the network and broadcast addresses, usable host range, subnet and wildcard masks, and an equal-split subnet table.
- Subnet Mask to CIDR Converter Calculator
- Convert between CIDR prefix length and dotted-decimal subnet mask in either direction, with the binary and hexadecimal mask, wildcard and block size.
- Hosts per Subnet Calculator
- Work out how many usable hosts fit in any IPv4 prefix, and find the smallest CIDR block that holds the host count you need, with RFC 3021 /31 support.
- VLSM Subnet Design Calculator
- Split an IPv4 block into right-sized subnets from your own host counts. Get network, mask, host range, broadcast and leftover space for each segment.
- Wildcard Mask Calculator (ACL)
- Convert a prefix or subnet mask into the Cisco wildcard mask, see exactly which addresses it matches, and copy a ready-made ACL or OSPF statement.
- IPv6 Subnet & Prefix Calculator
- Expand any IPv6 prefix into its first and last address, count the /64 subnets inside it, and see the exact address space. Built on RFC 4291 rules.