Calculate subnet mask, network address, broadcast and host range
Free online IP subnet calculator for network engineers, sysadmins, and students. Enter any IPv4 address and CIDR prefix (/0 to /32) to instantly calculate network address, subnet mask, broadcast address, first and last usable host addresses, total host count, and usable host count. Essential tool for network design, IP address planning, firewall configuration, and understanding subnetting concepts. All calculations happen instantly in your browser.
Subnetting is a fundamental skill in networking. Manually calculating subnet ranges, broadcast addresses, and host counts is tedious and error-prone. This tool instantly gives you all the values you need for network configuration, firewall rules, router setup, and IP address planning. Whether you're studying for a CCNA exam, designing a corporate network, or configuring cloud infrastructure, a subnet calculator saves time and prevents costly mistakes.
/24 = 254 usable hosts (most common for small networks). /16 = 65,534 usable hosts (medium networks). /8 = 16,777,214 usable hosts (large networks). /30 = 2 usable hosts (point-to-point links). /32 = 1 host (loopback, host routes). /28 = 14 usable hosts (small office segments). /22 = 1,022 usable hosts (medium office networks).
IP Subnet Calculator Online Free is useful when you need to complete a focused task quickly without installing desktop software, creating another account, or switching into a heavy workflow. It works well for quick checks, conversions, previews, cleanups, generation tasks, and everyday operations where speed and consistency matter. Free online IP subnet calculator for network engineers, sysadmins, and students. Enter any IPv4 address and CIDR prefix (/0 to /32) to instantly calculate network address, subnet mask, broadcast address, first and last usable host addresses, total host count, and usable host count. Essential tool for network design, IP address planning, firewall configuration, and understanding subnetting concepts. All calculations happen instantly in your browser.
Start with a small sample so you understand how IP Subnet Calculator Online Free handles your input, then apply it to the full task. Review the important fields, copy or export the result, and test it in the place where you plan to use it. This keeps the tool fast while still giving you a practical quality-control step before production use.
Before using the output, check formatting, special characters, line breaks, file names, URLs, units, numbers, and mobile display when relevant. If the result affects SEO, code, design, business documents, analytics, or customer-facing material, compare it against your original requirement and fix any context-specific detail before publishing.
Manual work is fine for one-off tasks, but repeated manual formatting or checking is slow and easy to make inconsistent. IP Subnet Calculator Online Free helps standardize the process, reduce copy-paste mistakes, and produce a cleaner starting point so you can spend more time on review, judgment, and improvement.
CIDR (Classless Inter-Domain Routing) notation represents an IP address and its subnet mask as a single value, e.g. 192.168.1.0/24 where /24 means the first 24 bits are the network portion.
Total hosts = 2^(32-prefix). Usable hosts = total - 2, because the network address and broadcast address cannot be assigned to devices.
A /32 subnet contains exactly one IP address. It's used for host routes and loopback addresses.
Most home routers use 192.168.1.0/24, which provides 254 usable host addresses (192.168.1.1 to 192.168.1.254).
The broadcast address is the last address in a subnet. Packets sent to this address are delivered to all hosts in the subnet. It cannot be assigned to a device.
Yes. IP Subnet Calculator Online Free is designed as a free browser-based utility for quick personal, learning, and professional workflows.
No. You can use IP Subnet Calculator Online Free directly in a modern browser such as Chrome, Edge, Safari, or Firefox.
Yes. The page is responsive and can be used on phones and tablets, although desktop is usually more comfortable for long input or repeated copy operations.
Use clean input, test with a small sample first, review the output carefully, and adjust any details that depend on your final use case.
In most cases, yes. You can use the generated or processed output in personal and commercial projects, but legal, financial, medical, or security-sensitive work should still be reviewed by a qualified person.
The tool is built for quick browser workflows. You should still avoid entering highly sensitive data unless the specific tool clearly states how the data is handled.
Many tools include copy or download actions. If a dedicated export is not available, you can usually copy the visible result manually.
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Tạo file .env và .env.example cho dự án.
Tạo .gitignore cho Node.js, Python, Java.
Tạo mock JSON data cho API testing.
Format và phân tích API response.
Test REST API: GET, POST, PUT, DELETE.
Giải thích regex, flags, capture group và cảnh báo pattern dễ lỗi.
Tạo OpenAPI JSON/YAML với params, auth và request body.
Chuyển đổi Binary, Hex, Base32.
Mã hóa/giải mã Base64.
Chuyển đổi Decimal, Binary, Hex.
Tạo CSS box-shadow trực quan.
Tính quyền file Linux.
