How many usable hosts are in a /24 subnet?
A /24 contains 256 total IPv4 addresses. In the traditional model, 254 are usable by hosts because the network and broadcast addresses are excluded.
Fast, private IPv4 calculations
IPv4 Subnet Calculator
Calculate the network address, broadcast address, usable host range, subnet masks and adjacent subnets.
Runs locally in your browser.
Subnet calculator
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Results
What is an IPv4 subnet calculator?
An IPv4 subnet calculator converts an IP address and CIDR prefix into the network address, broadcast address, subnet mask, wildcard mask, address range, and host capacity of the subnet. It helps you verify an addressing plan without calculating binary values by hand.
How to use the subnet calculator
- Enter an IPv4 address, such as 192.168.1.10.
- Enter a CIDR prefix from 0 to 32.
- Select Calculate subnet to generate the subnet details.
- Review the quick results, masks, capacity, adjacent subnets, and IPv4 classification.
Use the Copy buttons for values you need elsewhere. Use Load on an adjacent subnet to calculate it without entering the address manually.
CIDR prefixes, subnet masks, and wildcard masks
A CIDR prefix indicates the number of network bits in an IPv4 address. A /24 uses 24 network bits and leaves 8 host bits.
The subnet mask for a /24 is 255.255.255.0, and its wildcard mask is 0.0.0.255. The wildcard mask is the bitwise inverse of the subnet mask.
A larger prefix generally produces a smaller address block. Wildcard masks are commonly used in access control lists and some routing configurations.
Understanding your subnet results
Network and broadcast addresses
The network address is the first address of a traditional subnet and identifies the subnet itself. The broadcast address is normally the last address and is used to reach every host on that subnet. The /31 and /32 prefixes have different operational rules, explained below.
Usable host range
In a traditional IPv4 subnet, the usable host range excludes the network and broadcast addresses. For example, a /24 contains 256 total addresses and traditionally provides 254 usable host addresses.
Why /31 and /32 are different
A /31 contains two addresses and is commonly used on point-to-point links, where both addresses can act as endpoints instead of using separate network and broadcast addresses. A /32 represents one IPv4 address and is often used as a host route.
Example input
- IPv4 address
192.168.1.10- CIDR prefix
24
Frequently asked questions
What is the difference between CIDR and a subnet mask?
CIDR expresses the network boundary as a prefix length, such as /24. A subnet mask expresses the same boundary in dotted-decimal form, such as 255.255.255.0.
Can a /31 subnet be used?
Yes. A /31 is commonly used for a point-to-point link, where its two addresses are treated as endpoints and no separate broadcast address is needed.
What does a /32 prefix mean?
A /32 identifies one IPv4 address. It is commonly used for a host route or when a configuration must refer to one exact address.
What is a wildcard mask?
A wildcard mask is the bitwise inverse of a subnet mask. It is commonly used in access control lists and some routing configurations to identify which address bits must match.
Does this calculator send my IP address to a server?
No. The subnet calculation is performed locally in your browser, and the IPv4 address you enter is not sent to a server for the calculation.