Network Prefix Calculator

Enter an IPv4 address and prefix for instant analysis. View masks, hosts, wildcard, and ranges. Export clean results and verify subnet planning with confidence.

Calculator Form

Use the fields below to calculate network prefixes, host ranges, subnet counts, and binary breakdowns.

Example Data Table

IPv4 Address Prefix Network Address Broadcast Address Usable Hosts
192.168.10.34 /24 192.168.10.0 192.168.10.255 254
10.10.20.74 /26 10.10.20.64 10.10.20.127 62
172.16.5.130 /25 172.16.5.128 172.16.5.255 126
203.0.113.9 /30 203.0.113.8 203.0.113.11 2

Formula Used

Subnet Mask from Prefix: Mask bits are set to 1 for the prefix length. Remaining host bits are 0.

Representation: Subnet Mask = first n bits set, where n is the prefix length.

Network Address: Perform a bitwise AND between the IPv4 address and subnet mask.

Network = IP Address AND Subnet Mask

Broadcast Address: Combine the network address with the wildcard mask.

Broadcast = Network OR Wildcard Mask

Wildcard Mask: Invert every subnet mask bit.

Wildcard = 255.255.255.255 − Subnet Mask

Total Addresses: Count all host combinations left after the prefix.

Total Addresses = 2^(32 − Prefix)

Usable Hosts: Most IPv4 subnets reserve network and broadcast addresses.

Usable Hosts = Total Addresses − 2, except /31 and /32

Derived Subnets: Compare the current prefix with a larger parent block.

Subnets = 2^(Current Prefix − Base Prefix)

How to Use This Calculator

1. Enter a label for the subnet if you want a named report.

2. Provide a valid IPv4 address that belongs to the subnet you want to analyze.

3. Choose whether you want to work with a prefix length or a dotted subnet mask.

4. Add a base prefix when you want to measure how many child subnets exist inside a parent block.

5. Enter required hosts to compare current capacity with your expected device count.

6. Click Calculate Prefix to show the result block above the form.

7. Review network address, broadcast, host range, binary details, and recommendation fields.

8. Use the CSV or PDF buttons to export the generated results.

FAQs

1. What does a network prefix mean?

A network prefix shows how many leading bits identify the network portion of an IPv4 address. It is usually written in CIDR form, such as /24.

2. Why do I need both prefix and subnet mask options?

Engineers often receive address plans in different formats. Some documents use CIDR notation, while others use dotted masks. This calculator accepts either method.

3. How is the network address calculated?

The calculator applies a bitwise AND operation between the IPv4 address and subnet mask. That operation clears host bits and leaves only the network portion.

4. Why are /31 and /32 treated differently?

A /31 is commonly used for point-to-point links, where both addresses can be endpoints. A /32 represents exactly one host route.

5. What is a wildcard mask?

A wildcard mask is the inverse of the subnet mask. It is often used in access control lists and routing policies.

6. Can this calculator help with subnet planning?

Yes. Enter required hosts and an optional base prefix. The tool compares capacity, suggests a fitting prefix, and shows derived subnet counts.

7. Does the class value affect modern routing?

Not usually. Modern networks rely on CIDR rather than classful addressing. The class label is included only as a legacy reference.

8. What formats can I export from this page?

You can export the current result as a CSV file for spreadsheets or generate a PDF report for sharing, printing, or documentation.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.