IP & Network Tools
Free online IP address utilities for network engineers and developers. All calculations run in your browser — no data sent to servers.
Try CIDR Calculator →IP to Decimal
Convert IPv4 addresses to decimal, hex, binary, and octet notation. Bidirectional conversion.
IP ConverterCIDR Calculator
Calculate network address, broadcast, host range, wildcard mask, and total hosts from CIDR notation.
CIDRSubnet Mask Calculator
Convert between prefix length and subnet mask. Split subnets, find the right prefix for any host count.
SubnettingPort Number Lookup
Look up TCP/UDP port numbers, service names, and descriptions. Search by port number or service name.
PortsFrequently Asked Questions
CIDR (Classless Inter-Domain Routing) notation represents an IP address and its associated network prefix. For example, 192.168.1.0/24 means the network address is 192.168.1.0 and the subnet mask has 24 bits set (255.255.255.0), allowing 254 usable host addresses.
Each IPv4 address consists of 4 octets (0–255). Multiply the first octet by 2²⁴, the second by 2¹⁶, the third by 2⁸, and add the fourth. For example, 192.168.1.1 = (192×16777216) + (168×65536) + (1×256) + 1 = 3232235777. Use our IP Converter to do this automatically.
A subnet mask separates an IP address into the network portion and the host portion. Common masks: /8 = 255.0.0.0 (Class A), /16 = 255.255.0.0 (Class B), /24 = 255.255.255.0 (Class C). Use our Subnet Mask Calculator to convert between prefix lengths and masks.
No. Private IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) are reserved for private networks and are not routed on the public internet. They are used inside LANs, VPNs, and home networks.