Subnet Range Finder Form
Enter an IPv4 address with either CIDR notation or a dotted subnet mask. The result appears above this form after submission.
Example Data Table
| IPv4 Address | CIDR | Network Address | Broadcast Address | Usable Range | Usable Hosts |
|---|---|---|---|---|---|
| 192.168.10.35 | /27 | 192.168.10.32 | 192.168.10.63 | 192.168.10.33 - 192.168.10.62 | 30 |
| 10.24.5.140 | /20 | 10.24.0.0 | 10.24.15.255 | 10.24.0.1 - 10.24.15.254 | 4,094 |
| 172.16.8.200 | /30 | 172.16.8.200 | 172.16.8.203 | 172.16.8.201 - 172.16.8.202 | 2 |
Formula Used
Network address = IP address AND subnet mask.
Wildcard mask = 255.255.255.255 minus subnet mask.
Broadcast address = network address OR wildcard mask.
Total addresses = 2(32 − prefix).
Usable hosts = total addresses − 2 for most subnets, except /31 and /32 where special routing rules apply.
First usable host = network address + 1, and last usable host = broadcast address − 1 for standard host subnets.
How to Use This Calculator
1. Enter the IPv4 address you want to analyze.
2. Add either the CIDR prefix or the dotted subnet mask.
3. Enable the /31 option when checking point-to-point links.
4. Enable binary output if you want the bit-level breakdown.
5. Click Find Subnet Range to generate the subnet block.
6. Review the result section above the form for masks, ranges, host counts, and network identifiers.
7. Use the CSV or PDF buttons to export the generated result.
Frequently Asked Questions
1. What does a subnet range finder calculate?
It calculates the network address, broadcast address, first host, last host, wildcard mask, total addresses, and usable host count for an IPv4 subnet.
2. Can I enter a subnet mask instead of CIDR?
Yes. You can enter a dotted subnet mask like 255.255.255.224. The calculator validates it and derives the matching CIDR prefix automatically.
3. Why are /31 and /32 subnets special?
A /31 is often used on point-to-point links and may allow both addresses as endpoints. A /32 represents one exact host address only.
4. What is the wildcard mask used for?
The wildcard mask is the inverse of the subnet mask. It helps define matching ranges in routing, filtering, and access control rules.
5. Does this tool support private and public IP detection?
Yes. The result identifies whether the address falls in private, public, loopback, link-local, or multicast space.
6. Why does my prefix and mask combination fail?
The tool checks whether both values describe the same subnet. If they do not match, it stops the calculation and shows an error.
7. Can I export the result?
Yes. After calculation, you can download the subnet summary as a CSV file or generate a PDF report from the result section.
8. Does this calculator work for IPv6?
No. This version is built for IPv4 subnet analysis only. IPv6 addressing needs a separate calculator with different range logic.