BYTETOOLS

Subnet Calculator

Calculate network address, broadcast, usable host range and subnet mask from any IPv4 address and CIDR prefix. Free, instant and 100% in your browser.

192.168.1.0
Network address
192.168.1.63
Broadcast address
62
Usable hosts
192.168.1.1
First usable host
192.168.1.62
Last usable host
64
Total addresses

Subnet details

CIDR notation
192.168.1.0/26
Subnet mask
255.255.255.192
Wildcard mask
0.0.0.63
IP class (historical)
C
IP address (binary)
11000000.10101000.00000001.00001010
Subnet mask (binary)
11111111.11111111.11111111.11000000
Network (binary)
11000000.10101000.00000001.00000000

What is the Subnet Calculator?

The ByteTools Subnet Calculator takes an IPv4 address plus a CIDR prefix (or dotted subnet mask) and instantly works out everything about the subnet: network address, broadcast address, first and last usable host, usable host count, total addresses, wildcard mask and the binary view of both address and mask.

  • Network, broadcast, first/last usable host and host counts in one view
  • Accepts a CIDR prefix (/26) or a dotted subnet mask (255.255.255.192)
  • Wildcard mask, historical IP class and CIDR notation included
  • Binary view of the address, mask and network for learning subnetting
  • Correct RFC 3021 handling of /31 point-to-point links and /32 host routes
  • 100% client-side — your addressing plan never leaves the browser

How to use the Subnet Calculator

  1. 1

    Enter the IPv4 address you want to analyse (any host address in the subnet works).

  2. 2

    Enter the prefix length (26 or /26) or a dotted subnet mask like 255.255.255.192.

  3. 3

    Read the network, broadcast, first/last usable host and host counts from the stat cards.

  4. 4

    Check the details panel for the wildcard mask, IP class and binary breakdown.

  5. 5

    Use Copy summary to paste the whole result into documentation or a ticket.

About the Subnet Calculator

The ByteTools Subnet Calculator takes an IPv4 address plus a CIDR prefix (or dotted subnet mask) and instantly works out everything about the subnet: network address, broadcast address, first and last usable host, usable host count, total addresses, wildcard mask and the binary view of both address and mask.

It is built for network engineers, students preparing for CCNA-style exams, and developers configuring firewalls or cloud VPCs. Enter 192.168.1.10/26 and you immediately see the network 192.168.1.0, broadcast 192.168.1.63 and 62 usable hosts — with the /31 and /32 edge cases handled honestly per RFC 3021.

Everything is computed with pure 32-bit integer math locally in your browser. Nothing you type is uploaded or logged, so it is safe to use with real production addressing plans, and it keeps working offline.

Frequently asked questions

How do I calculate a subnet from an IP address and CIDR prefix?

AND the IP address with the subnet mask to get the network address, then OR the network with the inverted mask to get the broadcast. The usable hosts are everything between them. This calculator does that 32-bit math instantly and shows the binary working so you can verify it by hand.

How many usable hosts are in a /26 subnet?

A /26 contains 64 total addresses, of which 62 are usable — one is the network address and one is the broadcast. For example, 192.168.1.0/26 spans 192.168.1.0 to 192.168.1.63 with hosts from .1 to .62.

Why do /31 and /32 subnets show different usable host counts?

A /32 is a single host route: one address, no separate network or broadcast. A /31 has two addresses, and RFC 3021 allows both to be used as hosts on point-to-point links, so it shows 2 usable hosts instead of the classic formula's 0.

What is the difference between a subnet mask and a wildcard mask?

They are bitwise opposites. The subnet mask marks the network bits with 1s (255.255.255.192), while the wildcard mask marks the host bits with 1s (0.0.0.63). Cisco ACLs and OSPF statements use wildcard masks, which is why this calculator shows both.

Does this subnet calculator work offline?

Yes. Every calculation is plain integer arithmetic running in your browser tab — there are no lookups and no server calls. Once the page is loaded it works with no internet connection at all.

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