Subnet / CIDR Calculator — Free, No Upload, Browser-Based

Enter any IP address and CIDR prefix length to instantly see the network address, broadcast address, usable host range, subnet mask, wildcard mask, and total host count — all calculated in your browser. No IP address or network data is ever transmitted to a server, making it safe for inspecting internal or sensitive network ranges.

如何使用此工具

1. 輸入 IP 位址並調整前綴長度滑桿，或輸入如 10.0.0.0/8 的 CIDR 區塊。
2. 計算機會即時顯示網路位址、廣播位址、子網路遮罩、萬用字元遮罩與主機範圍。
3. 使用每列結果旁的複製按鈕複製任意單一數值。