CIDR/Subnet Converter
Convert CIDR, subnet masks & host without uploads or tracking.
✓ FAST
✓ LOCAL
CONVERSION
1
IP Address
Enter an IP to see specific network ranges.
2
Subnet or Hosts
Examples: 255.255.255.0, /24, 16
Calculates the smallest fitting subnet.
CIDR/Subnet clean and fast
This tool converts between CIDR prefixes and IPv4 subnet masks and calculates total IPs and usable hosts. Everything runs locally in your browser — no uploads, no tracking inside the calculator itself.
✓ Any valid mask
Supports all valid IPv4 masks (not just a small preset list).
✓ Host sizing
Enter required usable hosts and get the smallest matching CIDR + mask.