IP Subnet Calculator
Calculate network address, broadcast, usable hosts, and wildcard mask from IP and CIDR notation.
By Konstantin Iakovlev · Updated September 2026 · Source: RFC 4632 — Classless Inter-domain Routing (CIDR) (IETF, 2006); /31 links: RFC 3021
Usable Hosts
254
/24 network
Subnet Details
| Network Address | 192.168.1.0 |
| Broadcast Address | 192.168.1.255 |
| Subnet Mask | 255.255.255.0 |
| Wildcard Mask | 0.0.0.255 |
| First Usable Host | 192.168.1.1 |
| Last Usable Host | 192.168.1.254 |
| Usable Hosts | 254 |
| CIDR Notation | 192.168.1.0/24 |
Binary Subnet Mask
| Mask | 11111111.11111111.11111111.00000000 |
Common Subnets Reference
| /8 | 255.0.0.0 (16,777,214 hosts) |
| /16 | 255.255.0.0 (65,534 hosts) |
| /24 | 255.255.255.0 (254 hosts) |
| /25 | 255.255.255.128 (126 hosts) |
| /26 | 255.255.255.192 (62 hosts) |
| /27 | 255.255.255.224 (30 hosts) |
| /28 | 255.255.255.240 (14 hosts) |
| /30 | 255.255.255.252 (2 hosts) |
IPv4 only. Usable hosts exclude the network and broadcast addresses for /30 and shorter prefixes; a /31 point-to-point link uses both addresses as hosts (RFC 3021), and a /32 is a single host.
Use the IP Subnet Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.
Disclaimer: This calculator is for informational purposes only. Results are estimates based on the information you provide and the assumptions described on this page.
How It Works
Splitting a large IP range into smaller subnets is how administrators keep a network organized, contained, and secure. With IPv4 space running thin, deliberate subnet planning has a direct effect on performance and on how cleanly traffic is segmented.
Boundaries here come from CIDR (Classless Inter-Domain Routing) notation paired with subnet masks, which together fix the network range, the usable host range, and the broadcast address. The mask works through bitwise operations, marking which bits of an address belong to the network and which are left for hosts.
For prefixes up to /30, two addresses in every subnet are off-limits to hosts: the first is the network address and the last is the broadcast address, so usable hosts = 2^(32 − prefix) − 2. Overlooking that pair is a frequent slip, and because it trims two usable addresses from each subnet, leaving it out of your host count will overstate how many devices you can actually assign. The exceptions are /31, where RFC 3021 lets both addresses act as hosts on a point-to-point link, and /32, which names a single host; the calculator's menu runs from /8 to /32 and counts both /31 addresses as hosts.
Subnetting a Class C Network for a Small Office with 50 Devices
- 1 Start with the network 192.168.1.0/24 and determine you need subnets for different departments, requiring at least 14 host addresses per subnet.
- 2 Calculate the required subnet mask: since you need 14 hosts, you need 4 host bits (2^4 = 16 addresses, minus 2 reserved = 14 usable), leaving 28 network bits (/28).
- 3 The subnet mask becomes 255.255.255.240, creating 16 possible subnets (2^4) with 14 usable host addresses each.
- 4 First subnet: 192.168.1.0/28 with usable host range 192.168.1.1 to 192.168.1.14, providing adequate addressing for your 50-device office across multiple subnets.
Source: RFC 4632 — Classless Inter-domain Routing (CIDR) (IETF, 2006); /31 links: RFC 3021 · Last updated: September 2026
Frequently Asked Questions
What is a subnet mask and what does it do?
How many usable hosts does a /24 subnet have?
What is CIDR notation?
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