InfraNestInfraNest

Free tool

Subnet Calculator

Enter a CIDR block to instantly get the network address, broadcast, netmask, host range and usable hosts.

Network address192.168.1.0
Netmask255.255.255.0
Wildcard0.0.0.255
Broadcast192.168.1.255
Usable host range192.168.1.1 – 192.168.1.254
Usable hosts254
Total addresses256

Go beyond this tool. Manage Servers & Cloud across every provider — in one dashboard.

Get started free →

Subnetting splits an IP network into smaller blocks. This calculator does the binary maths for you — handy when planning private networks, firewall rules or cloud VPCs.

Enter any IPv4 CIDR like 10.0.0.0/24 to see the full breakdown.

InfraNest

Run your cloud from one console

InfraNest manages your servers, private networks, firewalls and load balancers across providers, so you can plan and apply changes in one place.

  • Servers, volumes, firewalls & load balancers
  • Private networks across providers
  • Real metrics and a built-in console
  • A guided provisioning wizard

Other subnet sizes

Frequently asked questions

#What does the /24 in an IP address mean?

It is CIDR notation: the number of leading bits that identify the network rather than the host. A /24 fixes the first 24 bits, leaving 8 bits — 256 addresses — for hosts. The smaller the number, the bigger the block.

#Why are two addresses in a subnet unusable?

The first address identifies the network itself and the last is the broadcast address, so a /24 offers 254 usable hosts rather than 256. The exceptions are /31, which carries two usable addresses for point-to-point links, and /32, which is a single host.

#How many hosts fit in each subnet size?

A /24 gives 254 usable addresses, /25 gives 126, /26 gives 62, /27 gives 30, /28 gives 14 and /29 gives 6. Each step up the prefix halves the block.

#Which ranges can I use for a private network?

RFC 1918 reserves 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 for private use. Pick ranges that will not collide with a VPN peer or a future provider default — overlapping private ranges are painful to unpick later.

#What size should I pick for a cloud VPC?

Allocate the VPC generously and the subnets inside it modestly: a /16 for the VPC with /24s per subnet leaves room to add zones and services. Growing a subnet after the fact usually means rebuilding it.

From the blog

More free tools

One lookup is a snapshot

InfraNest keeps checking — across every domain you own — and tells you when the answer changes instead of when a customer does.

Free plan · No credit card required · Set up in minutes