How to read the result
Network address is the first address in the block.
Broadcast address is the final address in a conventional subnet.
Wildcard mask is the inverse of the subnet mask and is commonly used in ACL rules.
IPv4 NETWORK CALCULATOR
Calculate CIDR ranges
and subnets in seconds.
Find network boundaries, split a block into equal subnets, and check two IPv4 ranges for overlap before deployment.
01 · CIDR CALCULATOR
Get network boundaries from one address.
A host address is normalized to the start of its network block.
Normalized network
—
Broadcast—
Usable range—
Subnet mask—
Wildcard—
Total addresses—
Usable addresses—
Enter a CIDR to see how the range is calculated.
02 · SUBNET SPLITTER
Split a network into equal-sized blocks.
Choose a target prefix larger than the source prefix. Up to 1,024 rows are shown.
Split result—
| # | CIDR | First usable IP | Last usable IP | Broadcast | Usable |
|---|
Why does /24 split into four /26 blocks?
Increasing the prefix from 24 to 26 adds two network bits, producing 2² or four blocks.
Each /26 contains 64 addresses and normally provides 62 usable host addresses.
03 · CIDR OVERLAP CHECK
Check two address ranges before deployment.
Both values are normalized to their CIDR network boundaries before comparison.
Enter two CIDRs.
The result appears here.
—Why check overlap first?
Overlapping ranges make routing ambiguous across VPC peering, VPNs, and connected private networks.
IPv4 CIDR blocks are either separate, equal, or one contains the other after normalization.
Important calculation rules
Keep these exceptions in mind before applying a result to a network design.
/31 and /32 are special
A /31 can use both addresses on a point-to-point link, while a /32 represents one host. Conventional network and broadcast exclusions do not apply in the same way.
Host addresses are normalized
Entering 192.168.10.35/24 produces 192.168.10.0/24 because calculations use the actual block boundary.
Overlap affects connectivity
Overlapping private ranges can break routing between networks. Confirm the policies of your platform and devices before deployment.