CIDR to IP Range Converter
Convert any CIDR block to its first and last IP address and total address count. This CIDR to IP range converter is fast, private and runs entirely in your browser.
Turn a CIDR block into an IP range
CIDR notation (Classless Inter-Domain Routing) packs a whole block of addresses into a single string like 10.0.0.0/8. The number after the slash is the prefix length — how many leading bits are fixed for the network. This CIDR to IP range tool expands that shorthand into the concrete first address, last address, total count and usable host range so you can read it at a glance.
How to use it
- Enter a CIDR block, for example
192.168.1.0/24or172.16.0.0/12. - The first address is the network address; the last is the broadcast address.
- The total count is
2^(32 − prefix), and the usable host range excludes the network and broadcast (except for/31and/32). - Copy any value with its button — everything is computed locally.
Prefix arithmetic is quick once it clicks: every extra bit of prefix halves the block. A /8 is 16,777,216 addresses, a /9 is half that, and so on down to a single address at /32. Learn more in what is a subnet mask.
Want the opposite conversion? The IP Range to CIDR calculator turns a start and end address back into CIDR blocks. For full subnet details including the mask and wildcard, use the IPv4 Subnet Calculator. If you are new to addressing, our guide on what an IP address is is a good start.
Frequently asked questions
How do I convert a CIDR block to an IP range?
Type a CIDR block such as 10.0.0.0/8 and the tool applies the prefix to find the first address (the network address) and the last address (the broadcast). It also shows the total number of addresses and the usable host range.
How many addresses are in a CIDR block?
A CIDR block holds 2^(32 − prefix) addresses. So a /24 has 256, a /16 has 65,536 and a /8 has 16,777,216 addresses.
What is the difference between the total range and the usable range?
The total range spans the network address to the broadcast address. The usable host range drops those two (except for /31 and /32), so a /24's usable range is the network address plus one through the broadcast minus one.
Does this run on a server?
No. The conversion is pure JavaScript running in your browser, so your CIDR blocks never leave your device.
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