About this tool
Enter a CIDR prefix, a subnet mask or a wildcard mask and instantly see all three equivalent forms. The conversion happens locally in your browser.
Frequently asked questions
What input formats are accepted?
A CIDR like /24, a subnet mask like 255.255.255.0, or a wildcard mask like 0.0.0.255 — it detects which one you entered.
What is a wildcard mask used for?
It is the inverse of a subnet mask and is used in access control lists and OSPF to match ranges of addresses.