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CIDR calculator

CIDR Calculator

Paste a CIDR (like 192.168.10.0/24) to see the network boundary, host range, masks, and counts.

Calculated 255.255.255.0 256
CIDR notationIPv4 only

Calculated status

/24

IP position in block

1/256

Aligned0%

Total

256

Usable

254

Usable index

N/A

Address type

Private (RFC 1918)

Reserved Broadcast Boundary-aligned

Quick guide

  • The tool computes the true network CIDR even if you paste a host IP.
  • Total addresses are always 2^(32 - prefix).
  • /31 and /32 are special: they do not use broadcast and have different “usable” rules.

Normalized network CIDR

192.168.10.0/24

CIDR summary

Normalized network CIDR

192.168.10.0/24

Prefix / host bits

/24 • 8 host bits

Block size / increment

256 • 1 (3rd octet)

Boundary aligned

Yes

Address range

Network address (first)

192.168.10.0

Last address

192.168.10.255

Broadcast address

192.168.10.255

Usable range

192.168.10.1 — 192.168.10.254

First / last usable

192.168.10.1 — 192.168.10.254

Mask & counts

Subnet mask

255.255.255.0

Wildcard mask

0.0.0.255

Usable / total

254 / 256

Address type

Private (RFC 1918)

Neighbors & notes

Same prefix

Previous network

192.168.9.0/24

Next network

192.168.11.0/24

Input role

Network address

Not routable on the public internet.

Binary view (advanced)

Network

11000000 10101000 00001010 00000000

Mask

11111111 11111111 11111111 00000000

Wildcard

00000000 00000000 00000000 11111111

All calculated output (copy-friendly) 

Input CIDR: 192.168.10.0/24
Normalized network CIDR: 192.168.10.0/24
Aligned to network boundary: Yes
Input IP role: Network address

Network address (first): 192.168.10.0
Last address: 192.168.10.255
Broadcast address: 192.168.10.255
First usable: 192.168.10.1
Last usable: 192.168.10.254
Usable range: 192.168.10.1 — 192.168.10.254
IP index in block: 1 of 256 (0%)
Usable index: N/A
Usable addresses: 254
Total addresses: 256

Prefix length: /24
Host bits: 8
Subnet mask: 255.255.255.0
Wildcard mask: 0.0.0.255
Increment: 1 (3rd octet)

Previous network (same size): 192.168.9.0/24
Next network (same size): 192.168.11.0/24

Address type: Private (RFC 1918)
Notes: Not routable on the public internet.

Network (binary): 11000000 10101000 00001010 00000000
Mask (binary): 11111111 11111111 11111111 00000000
Wildcard (binary): 00000000 00000000 00000000 11111111