Convert between CIDR notation and IP address ranges. Expand CIDR notation. Supports IPv4 and IPv6.
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Use a dash (-) or comma (,) to separate start and end IPs.
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CIDR (Classless Inter-Domain Routing) notation is a compact method for specifying IP addresses and their associated routing prefix. It's a way to allocate IP addresses and route IP packets.
A CIDR address looks like a normal IP address, followed by a slash and a number. For example: 192.168.1.0/24
The number after the slash represents the number of bits in the network prefix. In IPv4, this can range from 0 to 32.
This tool allows you to convert between CIDR notation and IP address ranges. This is also called expanding and collapsing CIDR ranges. You can expand and collapse IPv4 and IPv6 ranges. And — like all of our tools — it's completely free to use.
| CIDR | Subnet Mask | Number of Addresses |
|---|---|---|
| /32 | 255.255.255.255 | 1 |
| /24 | 255.255.255.0 | 256 |
| /16 | 255.255.0.0 | 65,536 |
| /8 | 255.0.0.0 | 16,777,216 |
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