CIDR Subnet Calculator
Plan VPCs, firewalls and VPN routes with an IPv4 CIDR calculator: network, broadcast, mask, wildcard, host range and “is this IP inside?” — all local.
CIDR / subnet calculator for IT, cloud & VPC planning
Network engineers and cloud admins live in CIDR blocks: VPC design, firewall rules, VPN routes. This IPv4 subnet calculator runs locally—paste 10.0.0.0/16 and get network, broadcast, mask, usable hosts and range without shipping diagrams to a random site.
- Network, broadcast, netmask, wildcard
- First / last usable host and host counts
- Membership check — is this IP inside the CIDR?
Frequently asked questions
Do you support IPv6?
This calculator is IPv4/CIDR (e.g. 10.0.0.0/16). IPv6 can be added later; most corporate VPC worksheets still start with IPv4.
Is my network diagram uploaded?
No. All math is bitwise arithmetic in the browser.
Comments (0)
Questions, ideas or a bug in “CIDR Subnet Calculator”? Leave a comment, rate the tool, or reply to others.
No comments yet. Be the first to share your feedback!