IP Address & CIDR Calculator
Calculate IPv4 network ranges, subnet masks, and usable hosts from an address and CIDR prefix
Network details
| Input CIDR | 192.168.1.42/24 |
|---|---|
| Subnet mask | 255.255.255.0 |
| Wildcard mask | 0.0.0.255 |
| Network address | 192.168.1.0 |
| Broadcast address | 192.168.1.255 |
| First usable address | 192.168.1.1 |
| Last usable address | 192.168.1.254 |
| Total addresses | 256 |
| Usable hosts | 254 |
| Address scope | Private |
What this tool does
Calculate the network address, broadcast address, subnet mask, usable host range, and address count from an IPv4 address and CIDR prefix. It is useful for planning networks and checking configuration values.
Common use cases
- Check a subnet before configuring a router, firewall, or cloud network.
- Confirm whether an IPv4 address belongs to the expected network range.
- Choose a CIDR size that provides enough usable host addresses.
How to use it
- Enter an IPv4 address, such as 192.168.10.42.
- Choose a CIDR prefix from 0 to 32, such as 24.
- Select Calculate and review the network range and usable host count.
Input and output example
Input: 192.168.10.42 / 24
Output: Network: 192.168.10.0, broadcast: 192.168.10.255, usable range: 192.168.10.1–192.168.10.254, 254 hosts
Important notes
- The calculator currently supports IPv4 only, not IPv6.
- A /31 is treated as two point-to-point endpoints and a /32 as one host route.
- The address scope does not confirm real-world reachability or firewall access.
Frequently asked questions
- What does /24 mean in CIDR notation?
- It means that the first 24 of the 32 IPv4 bits form the network portion. A typical /24 contains 256 total addresses.
- Is the IP address sent to a server?
- No. The address and calculated results remain in your browser.