ToolKitSphereIP CIDR Subnet & Range Calculator
Calculate network IP, broadcast IP, netmask, wildcard mask, and usable host count from CIDR.
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This CIDR subnet calculator takes any IP address with a CIDR prefix, like 192.168.1.0/24, and instantly computes the network address, broadcast address, subnet mask, wildcard mask, and the number of usable hosts. It's built for network engineers, sysadmins, and students learning subnetting who need accurate results without manually working through binary math. Rather than calculating a netmask by hand or guessing host ranges, this ip range calculator does the arithmetic for you and shows the full breakdown of the subnet in one view. It's equally useful for planning VLAN segmentation, configuring firewall rules, or double-checking homework on classless inter-domain routing. All calculations happen instantly in your browser - no address is ever sent to a server, and there's nothing to install or sign up for. Enter an IP address and CIDR prefix below to see the complete subnet breakdown.
Features
- Calculates network address and broadcast address from CIDR notation
- Computes subnet mask and wildcard mask
- Shows total and usable host counts per subnet
- Displays the full usable host address range
- Supports CIDR prefixes from /0 through /32
- Instant recalculation as you change the prefix length
- Handles standard private and public IPv4 ranges
Why use this ip cidr subnet & range calculator?
- Instant calculations with no manual binary math
- Fully private - no IP or network data is transmitted
- Accurate results based on standard subnetting rules
- Clear layout that's useful for both learning and production work
- Free to use with no signup or limits
Frequently asked questions
How many usable hosts are in a /24 subnet?
A /24 subnet has 256 total addresses, with 254 usable host addresses after subtracting the network and broadcast addresses.
What's the difference between netmask and wildcard mask?
The netmask marks network bits with 1s and host bits with 0s, while the wildcard mask is its inverse, commonly used in ACLs and OSPF configuration.
What is the broadcast address used for?
The broadcast address is the highest address in a subnet, reserved for sending data to all hosts on that network segment.
Can this calculator handle a /32 CIDR?
Yes, a /32 represents a single host address with no usable range beyond that one IP.
Does this tool support IPv6 CIDR calculations?
This calculator is focused on IPv4 subnetting; use the dedicated IPv4 to IPv6 converter for IPv6-related conversions.
What CIDR prefix gives exactly 8 usable hosts?
A /29 subnet provides 8 total addresses and 6 usable host addresses after reserving the network and broadcast addresses.
Why does a /31 subnet have no usable hosts in classic subnetting?
A /31 has only 2 addresses total; under RFC 3021 both can be used for point-to-point links without a traditional broadcast address.