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Free & Open Source
Professional Subnet Calculator
IPv4/IPv6 network planning for
AWS
,
Azure
&
Google Cloud
IPv4 & IPv6
Cloud Provider Modes
Split & Join Subnets
Terraform & IaC Export
Save & Load
Network Configuration
Enter an IP address and CIDR prefix. Select a cloud provider mode to account for reserved IPs.
IP Version
IP Address
CIDR Prefix
Mode
Calculate Subnet
Frequently Asked Questions
Common questions about subnet calculation, CIDR notation, and cloud networking
What is a subnet calculator?
How do I calculate a subnet mask?
What is CIDR notation?
How many usable hosts in a /24 subnet?
What IP addresses does AWS reserve in a VPC subnet?
What IP addresses does Azure reserve in a VNet subnet?
What IP addresses does Google Cloud reserve in a VPC subnet?
What's the difference between IPv4 and IPv6 subnetting?
How do I split a subnet into smaller networks?
Is this subnet calculator free to use?
How do I save and load subnet configurations?
How do I export subnets to Terraform, CloudFormation, or Bicep?
Load
Ctrl+O
Save
Ctrl+S