CIDR and subnet calculator

IP to CIDR - simple

Input lower and upper IP (either IPv4 or IPv6) of the range - the tool will calculate best matching CIDR range. Subnet will be included in result.



IP to CIDR - advanced

Input at least two IP's (IPv4 and/or IPv6), domainnames or CIDR ranges to include - the tool will calculate best matching CIDR ranges. Subnet will be included in result. Seperate by space, tab, newline or comma.


IPv4 max network prefix:

IPv6 max network prefix:

Reverse - CIDR to IP + subnet

Input one or more CIDR ranges to get info of IP addresses and subnet.


IP to CIDR result

CIDR's ready to copy





66.220.149.251/32


CIDR
66.220.149.251/32

This is a single IP (/32) - you may just as well write it as 66.220.149.251.

lower IP
66.220.149.251


upper IP
66.220.149.251


subnet
255.255.255.255


broadcast
66.220.149.251


count
1



byte no: 1 2 3 4
bit no:

 1-8

 9-16

 17-24

 25-32
value: 66 220 149 251
bit pattern:
0
1
0
0
0
0
1
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
0
1
1
1
1
1
1
0
1
1
prefix:
/32
 


66.220.155.0/25


CIDR
66.220.155.0/25


lower IP
66.220.155.0


upper IP
66.220.155.127


subnet
255.255.255.128


broadcast
66.220.155.127


count
128



byte no: 1 2 3 4
bit no:

 1-8

 9-16

 17-24

 25-32
value: 66 220 155 0
bit pattern:
0
1
0
0
0
0
1
0
1
1
0
1
1
1
0
0
1
0
0
1
1
0
1
1
0
0
0
0
0
0
0
0
prefix:
/25
 


66.220.155.128/25


CIDR
66.220.155.128/25


lower IP
66.220.155.128


upper IP
66.220.155.255


subnet
255.255.255.128


broadcast
66.220.155.255


count
128



byte no: 1 2 3 4
bit no:

 1-8

 9-16

 17-24

 25-32
value: 66 220 155 128
bit pattern:
0
1
0
0
0
0
1
0
1
1
0
1
1
1
0
0
1
0
0
1
1
0
1
1
1
0
0
0
0
0
0
0
prefix:
/25
 


69.171.232.1/32


CIDR
69.171.232.1/32

This is a single IP (/32) - you may just as well write it as 69.171.232.1.

lower IP
69.171.232.1


upper IP
69.171.232.1


subnet
255.255.255.255


broadcast
69.171.232.1


count
1



byte no: 1 2 3 4
bit no:

 1-8

 9-16

 17-24

 25-32
value: 69 171 232 1
bit pattern:
0
1
0
0
0
1
0
1
1
0
1
0
1
0
1
1
1
1
1
0
1
0
0
0
0
0
0
0
0
0
0
1
prefix:
/32
 


69.171.232.255/32


CIDR
69.171.232.255/32

This is a single IP (/32) - you may just as well write it as 69.171.232.255.

lower IP
69.171.232.255


upper IP
69.171.232.255


subnet
255.255.255.255


broadcast
69.171.232.255


count
1



byte no: 1 2 3 4
bit no:

 1-8

 9-16

 17-24

 25-32
value: 69 171 232 255
bit pattern:
0
1
0
0
0
1
0
1
1
0
1
0
1
0
1
1
1
1
1
0
1
0
0
0
1
1
1
1
1
1
1
1
prefix:
/32
 


69.171.244.0/25


CIDR
69.171.244.0/25


lower IP
69.171.244.0


upper IP
69.171.244.127


subnet
255.255.255.128


broadcast
69.171.244.127


count
128



byte no: 1 2 3 4
bit no:

 1-8

 9-16

 17-24

 25-32
value: 69 171 244 0
bit pattern:
0
1
0
0
0
1
0
1
1
0
1
0
1
0
1
1
1
1
1
1
0
1
0
0
0
0
0
0
0
0
0
0
prefix:
/25
 


69.171.244.128/25


CIDR
69.171.244.128/25


lower IP
69.171.244.128


upper IP
69.171.244.255


subnet
255.255.255.128


broadcast
69.171.244.255


count
128



byte no: 1 2 3 4
bit no:

 1-8

 9-16

 17-24

 25-32
value: 69 171 244 128
bit pattern:
0
1
0
0
0
1
0
1
1
0
1
0
1
0
1
1
1
1
1
1
0
1
0
0
1
0
0
0
0
0
0
0
prefix:
/25
 


69.171.245.0/25


CIDR
69.171.245.0/25


lower IP
69.171.245.0


upper IP
69.171.245.127


subnet
255.255.255.128


broadcast
69.171.245.127


count
128



byte no: 1 2 3 4
bit no:

 1-8

 9-16

 17-24

 25-32
value: 69 171 245 0
bit pattern:
0
1
0
0
0
1
0
1
1
0
1
0
1
0
1
1
1
1
1
1
0
1
0
1
0
0
0
0
0
0
0
0
prefix:
/25
 


69.171.245.128/25


CIDR
69.171.245.128/25


lower IP
69.171.245.128


upper IP
69.171.245.255


subnet
255.255.255.128


broadcast
69.171.245.255


count
128



byte no: 1 2 3 4
bit no:

 1-8

 9-16

 17-24

 25-32
value: 69 171 245 128
bit pattern:
0
1
0
0
0
1
0
1
1
0
1
0
1
0
1
1
1
1
1
1
0
1
0
1
1
0
0
0
0
0
0
0
prefix:
/25
 

Log

  • Lookup of 'smtpin.vvv.facebook.com' - 1 IP's found
    66.220.149.251
  • In order to explode '66.220.155.0/24' into /25 CIDR ranges, 4 additional IP's has been added.
  • In order to explode '69.171.244.0/23' into /25 CIDR ranges, 8 additional IP's has been added.
  • 15 IP's parsed from input
  • Based on max prefix /25, IP 66.220.149.251 cannot be grouped into any CIDR range.
  • Creating CIDR '66.220.155.0/25' based upon input '66.220.155.0' and '66.220.155.127'
  • Creating CIDR '69.171.244.0/25' based upon input '69.171.244.0' and '69.171.244.127'
  • Based on max prefix /25, IP 69.171.232.1 cannot be grouped into any CIDR range.
  • Based on max prefix /25, IP 69.171.232.255 cannot be grouped into any CIDR range.
  • Creating CIDR '66.220.155.128/25' based upon input '66.220.155.128' and '66.220.155.255'
  • Creating CIDR '69.171.244.128/25' based upon input '69.171.244.128' and '69.171.244.255'
  • Creating CIDR '69.171.245.0/25' based upon input '69.171.245.0' and '69.171.245.127'
  • Creating CIDR '69.171.245.128/25' based upon input '69.171.245.128' and '69.171.245.255'