Calculator Inputs
Enter an IPv4 address and calculate by CIDR prefix or subnet mask.
Example Data Table
Use these sample values to understand how the calculator reports subnet planning details.
| IPv4 Address | Prefix | Subnet Mask | Network | Broadcast | Usable Hosts |
|---|---|---|---|---|---|
| 192.168.10.14 | /24 | 255.255.255.0 | 192.168.10.0 | 192.168.10.255 | 254 |
| 10.25.8.77 | /20 | 255.255.240.0 | 10.25.0.0 | 10.25.15.255 | 4,094 |
| 172.16.5.130 | /26 | 255.255.255.192 | 172.16.5.128 | 172.16.5.191 | 62 |
Formula Used
Subnet mask from prefix: mask = 32-bit value with the first n bits set to 1, where n equals the CIDR prefix.
Network address: network = IP address AND subnet mask.
Broadcast address: broadcast = network OR wildcard mask.
Wildcard mask: wildcard = 255.255.255.255 minus subnet mask.
Total addresses: 2(32 - prefix).
Usable hosts: 2(32 - prefix) - 2 for most subnets, except /31 and /32 where host rules differ.
How to Use This Calculator
- Enter a valid IPv4 address such as 192.168.10.14.
- Choose whether to calculate by CIDR prefix or subnet mask.
- Enter the prefix length or the subnet mask value.
- Click Calculate Network to display results above the form.
- Review network, broadcast, host range, wildcard, binary values, and address classification.
- Use the CSV or PDF buttons to export the calculated results.
Frequently Asked Questions
1. What does an IP network calculator do?
It converts an IPv4 address and prefix into subnet details like network address, broadcast address, usable host range, wildcard mask, and host capacity.
2. What is CIDR notation?
CIDR notation writes an address with a slash and prefix length, such as 192.168.1.10/24. The prefix shows how many leading bits belong to the network.
3. Why are /31 and /32 subnets special?
A /31 subnet is often used on point-to-point links, while /32 identifies one host only. Traditional network and broadcast reservations do not apply the same way.
4. What is the difference between subnet mask and wildcard mask?
The subnet mask marks network bits with ones. The wildcard mask is the inverse, marking host bits with ones. It is often used in routing and access rules.
5. Can this calculator detect private addresses?
Yes. It labels common private ranges, loopback, link-local, multicast, and reserved spaces, helping with quick address classification during troubleshooting or planning.
6. Does this tool support IPv6?
No. This version focuses on IPv4 subnet analysis. IPv6 requires different formatting, prefix handling, and address expansion logic.
7. When should I export results?
Export results when documenting network plans, validating classroom exercises, sharing subnet calculations, or keeping audit-ready records for operational changes.