Developer·Updated 2026-04-22
IP Subnet Calculator (CIDR)
Network, broadcast, host range and subnet mask for any IPv4 CIDR.
IP Subnet Calculator (CIDR)
How it works
- 1.
Enter IP
Enter your page title and meta description. Live character counters go green for optimal (title ≤ 60, description ≤ 160) and warn when you run long.
- 2.
Set CIDR
The OG image URL must be absolute (with https://) and ideally 1200×630 pixels. LinkedIn, Facebook, and X accept this size natively.
- 3.
Read results
Copy the generated block and paste it into your page's <head>. It includes OG tags, Twitter Card tags, and canonical — everything needed for social unfurls.
FAQ
Does this support IPv6?+
Currently IPv4 only. IPv6 support is on the roadmap.
What happens with /31 and /32?+
Per RFC 3021: /31 exposes two usable hosts, /32 is a single host route.
Are private ranges detected?+
Yes: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 are flagged as private.