CIDR Range
Calculate IP ranges from CIDR notation and check if an IP is within range
How to use CIDR Range
- 1Enter an IPv4 or IPv6 address with its prefix length, e.g. 10.0.0.0/24.
- 2Read the network address, first/last usable host, and broadcast (IPv4).
- 3Read the total address count and the range the subnet covers.
CIDR range and subnet bounds
addresses = 2^(hostBits); hostBits = 32 − prefix (IPv4)CIDR (Classless Inter-Domain Routing) expresses a network as an address plus a prefix length that marks the network portion of the bits.
A /24 leaves 8 host bits, giving 256 addresses (254 usable in IPv4 after network and broadcast). Larger prefixes mean smaller subnets.
Frequently asked questions
What is the difference between /24 and /16?
A /16 borrows fewer host bits, so it covers 65,536 addresses; a /24 covers only 256.
Why are usable hosts two less than total?
IPv4 reserves the network address and the broadcast address, leaving the rest usable.
Does IPv6 use broadcast?
No; IPv6 has no broadcast, so all addresses in a prefix are effectively usable.
More Tools
Visual Subnet
Calculate IPv4 and IPv6 subnet details with CIDR notation
CIDR Range
Calculate IP ranges from CIDR notation and check if an IP is within range
IP Address
Classify IP addresses by class (A-E) and identify public/private status
Throughput
Calculate network throughput from data transferred and time