CIDR Calculator
CIDR Calculator
Calculate IPv4 subnet details from CIDR notation: network address, broadcast, host range, subnet mask, wildcard mask, host count, and binary representation. Subnet splitter, VLSM, IPv6 support, and a CIDR aggregation/overlap checker.
Enter a CIDR address to inspect the subnet
Calculate IPv4/IPv6 subnet details, split a CIDR block into equal subnets, plan VLSM allocations, aggregate/check overlap across a list of CIDR blocks, or simulate a router's longest-prefix-match lookup against a routing table.
CIDR Calculator
Calculate IPv4 subnet details from CIDR notation: network address, broadcast, host range, subnet mask, wildcard mask, host count, and binary representation. Subnet splitter, VLSM, IPv6 support, and a CIDR aggregation/overlap checker.
Common uses
- Calculate the host range for 10.0.0.0/16
- Split 192.168.0.0/24 into 4 equal subnets
- Check a list of CIDR blocks for overlaps
- Summarize multiple CIDR blocks into the fewest supernets
Frequently asked questions
Can I use CIDR Calculator to calculate the host range for 10.0.0.0/16?
Yes. CIDR Calculator can calculate the host range for 10.0.0.0/16, directly in your browser.
Can I use CIDR Calculator to split 192.168.0.0/24 into 4 equal subnets?
Yes. CIDR Calculator can split 192.168.0.0/24 into 4 equal subnets, directly in your browser.
Can I use CIDR Calculator to check a list of CIDR blocks for overlaps?
Yes. CIDR Calculator can check a list of CIDR blocks for overlaps, directly in your browser.
Is my data uploaded to a server?
No. This tool runs entirely in your browser — your input is processed locally on your device and is never uploaded or stored on a server.