IP address range calculator
Shows where an IPv4 block starts and ends, plus the range you can assign to devices.
For example 192.168.1.10 or 192.168.1.10/24
- First address
- Last address
- First host
- Last host
- Total addresses
- Usable hosts
- CIDR notation
Runs in your browser. Nothing you enter is sent to our server.
About this tool
You need a range when setting up a DHCP pool, a firewall rule or an allowlist, or when checking a block assigned by your provider. The calculator takes an IPv4 address and prefix and returns the block boundaries.
The full range includes the network and broadcast addresses. The host range excludes them, and that is usually what goes into DHCP settings.
How to use
- Enter an address such as
192.168.0.0and choose a prefix — or paste192.168.0.0/22. - Read the first and last address of the block and the host range.
- Copy the boundaries with the buttons next to them.
Examples
192.168.0.0/22
Block 192.168.0.0 – 192.168.3.255 (1024 addresses), hosts 192.168.0.1 – 192.168.3.254
203.0.113.77/29
Block 203.0.113.72 – 203.0.113.79 (8 addresses), hosts .73 – .78
Frequently asked questions
Can I convert an arbitrary range to CIDR?
Not yet: the calculator starts from an address and prefix. An arbitrary range (say .10–.20) usually does not fit a single CIDR block anyway.
Is the network address part of the range?
It is part of the block’s full range, but it cannot be assigned to a device, so the host range starts at the next address.
Why doesn’t the range start at the address I entered?
A block always starts at a multiple of its size. 203.0.113.77/29 belongs to the block that begins at 203.0.113.72.