IP Subnet Calculator

Calculate subnets, CIDR notation, network addresses, and host ranges for IPv4 networks.

Professional subnet calculator for network administrators and engineers

Calculation Method

Use CIDR prefix (e.g., /24)

Use subnet mask (e.g., 255.255.255.0)

Network Information

IP Address

CIDR Notation

CIDR Information

IP Address Range Start IP Address

End IP Address

Or Calculate from Hosts

Network Address

Required Hosts

VLSM Network Information

Major Network

Subnet Requirements Format: Name:Hosts, Name:Hosts

Subnet Calculator Tab: Calculate network properties from IP address and CIDR/subnet mask
CIDR Calculator Tab: Find CIDR notation from IP range or calculate based on host requirements
VLSM Calculator Tab: Calculate Variable Length Subnet Masking for efficient IP allocation
All calculations support IPv4 addresses in dotted-decimal notation
Results include binary representation for educational purposes

CIDR	Subnet Mask	Hosts	Usable Hosts	Class
/30	255.255.255.252	4	2	Point-to-point
/29	255.255.255.248	8	6	Small network
/28	255.255.255.240	16	14	Small network
/27	255.255.255.224	32	30	Small network
/26	255.255.255.192	64	62	Medium network
/24	255.255.255.0	256	254	Class C
/16	255.255.0.0	65,536	65,534	Class B
/8	255.0.0.0	16,777,216	16,777,214	Class A