CIDR / Subnet Calculator
Enter an IPv4 or IPv6 CIDR block to compute the network, broadcast, usable host range, masks and host count. Everything runs in your browser.
Result
Enter a CIDR and click Calculate.
Related tools
How to use
1
Enter a CIDR
Type any IPv4 or IPv6 address with a prefix length.
2
Calculate
Network, broadcast, mask and ranges are computed instantly.
3
Copy values
Click any value to copy it to your clipboard.
Frequently Asked Questions
CIDR writes an IP followed by a slash and a prefix length (e.g. 192.168.1.0/24). The prefix length is the number of leading network bits; the rest address hosts.
256 total addresses. With network and broadcast reserved, 254 are usable.
The bitwise inverse of the subnet mask, used in ACLs. For /24 the mask is 255.255.255.0 and the wildcard is 0.0.0.255.
No. All subnet math runs locally in your browser.
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