IP/CIDR Address Calculator
Plan subnet masks based on host count.
Subnet Mask Converter
IPAddress Base Converter
IPCalculator user guide
IPThis calculator is an essential professional tool for network engineers and developers, providing comprehensive IP address calculation, subnet planning, mask conversion, and base conversion. It supports a wide range of IPv4 calculation needs, including CIDR calculation, subnetting, and network planning, offering a complete solution for network configuration and management.。
Key features
🌐 IP/CIDRAddress calculation
Based on the IP address and CIDR length or subnet mask, it automatically calculates key information such as the network address, broadcast address, and usable address range.。
Input:
192.168.1.0/24Output:
Network address：
192.168.1.0Broadcast address：
192.168.1.255Usable addresses：
192.168.1.1 - 192.168.1.254Usable hosts：
254📊 Smart subnet planning
Based on the required number of hosts, automatically calculates the optimal subnet mask configuration to ensure efficient use of address resources.。
- Recommend subnet masks based on host count.
- Calculate the actual number of usable addresses.
- Show network bits and host bits.
- Provides multiple subnetting options.
- Supports VLSM (variable-length subnet masks)
- Optimize address space utilization.
🔄 Subnet Mask Converter
Convert subnet masks between decimal, CIDR length, and hex formats, with real-time synchronized updates.。
- Dotted-decimal format (255.255.255.0)
- CIDRBit format (/24)
- Hex format (FFFFFF00)
- Binary format display
- Real-time format conversion
- Format validation and error messages
🔢 IPAddress base conversion
Convert IP addresses between dotted decimal, decimal integer, hex, binary, and octal formats.。
- Dotted decimal (192.168.1.1)
- Decimal number (3,232,235,777)
- Hex (C0A80101)
- Binary (11000000.10101000.00000001.00000001)
- Octal format
- One-click copy
How to use
Select a calculation
Choose IP/CIDR calculation, subnet planning, mask conversion, or base conversion as needed. Each module has its own input area and calculate button.。
Enter the parameters
Enter parameters such as the IP address, CIDR length, subnet mask, or host count in the corresponding input fields. The tool automatically validates the input format.。
View results
After clicking Calculate, the results are displayed in a clear format. Each result can be copied with one click for easy use in other tools.。
IPIP address and subnet mask basics
IPAddress（Internet Protocol Address）is short for Internet Protocol address — a unique identifier assigned to network devices. An IPv4 address consists of 32 binary bits, usually written in dotted-decimal notation, e.g. 192.168.1.1。Subnet maskUsed to distinguish the network portion from the host portion, a key parameter in network configuration.。
IPAddress classes explained
AClass addresses
Range：1.0.0.0 - 126.255.255.255
Default subnet mask: 255.0.0.0 (/8), supports about 16.77 million hosts, suitable for large networks.
BClass addresses
Range：128.0.0.0 - 191.255.255.255
Default subnet mask: 255.255.0.0 (/16), supports about 65,000 hosts, suitable for medium-sized networks.
CClass addresses
Range：192.0.0.0 - 223.255.255.255
Default subnet mask: 255.255.255.0 (/24), supports 254 hosts, suitable for small networks.
Private address
10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
Used for internal networks; not routed on the internet, accessing external networks via NAT.
Special addresses
127.0.0.1 (loopback), 0.0.0.0 (default route)
Reserved addresses for special purposes, used in network testing and configuration.
CIDR and subnetting
What isCIDR
Scenario:Classless Inter-Domain Routing (CIDR)
Format:IPaddress/prefix length (e.g.192.168.1.0/24)
Benefits:More flexible address allocation and a smaller routing table.
How subnetting works
Purpose：Split a large network into smaller ones.
Method：Borrow host bits for subnet bits.
Benefits：Improve address utilization and enhance network security.
VLSMTechnology
Concept：Variable-length subnet mask (VLSM)
Application：Allocate subnets of different sizes as needed.
Benefits:Maximize address space utilization.
Network planning use cases
🏢 Enterprise network planning
Assign appropriate subnets to different departments for network isolation and management.
🌐 Data center design
Plan server network segments to optimize network architecture and traffic distribution.
🔒 Network security configuration
Achieve network isolation through subnetting to improve security.
☁️ Cloud network configuration
Plan VPCs and subnets in cloud environments to optimize resource allocation.
📱 IoT deployment
Assign IP addresses to large numbers of IoT devices and manage the device network.
🔧 Network troubleshooting
Verify network configuration and pinpoint IP address conflicts.
Common subnet mask reference table
/24 - 255.255.255.0
254usable addresses, suitable for small office and home networks.
/23 - 255.255.254.0
510usable addresses, suitable for small and medium-sized enterprise networks.
/22 - 255.255.252.0
1022usable addresses, suitable for medium-sized enterprise networks.
/16 - 255.255.0.0
65534usable addresses, suitable for large enterprise networks.
Network calculation best practices
🎯 Plan your address space sensibly
Reserve enough room for growth to avoid frequent network re-planning.
📋 Document your network configuration
Document all subnet allocations to build complete network topology documentation.
🔍 Review address usage regularly
Monitor address usage and promptly reclaim unused address ranges.
🛡️ Consider security boundaries
Establish security boundaries through subnetting and enforce network access control.