CIDR / 子網路計算器

輸入一個CIDR區塊來計算子網路詳情，包括網路位址、廣播位址、可用範圍和子網路遮罩。所有處理均在您的瀏覽器中完成。

CIDR Notation

Common Subnets

About CIDR / Subnet Calculator

CIDR (Classless Inter-Domain Routing) notation combines an IP address with a prefix length to define a network. This tool calculates all subnet details from a CIDR block. All processing runs in your browser.

Network Address: The first address in the subnet, identifies the network itself.
Broadcast Address: The last address in the subnet, used for broadcasting to all hosts.
Usable Range: Addresses available for host assignment (excludes network and broadcast).
Subnet Mask: Determines which bits identify the network vs. host portion.