Visual Subnet Calculator (Azure Edition)

Enter the Azure Virtual Network (VNet) Address you wish to subnet:

Network Address Mask bits
/

Show columns:

Click below to split and join subnets.



Subnet name Subnet address Netmask Range of addresses Azure Subnet Useable IPs Azure Usable Hosts Divide Join


Reserved Subnet Name min. Size of Subnet Max. Size of Subnet Recommand Size of Subnet Related Azure Services
GatewaySubnet /27 /27 /27 Azure Virtual Network Gateway / ExpressRoute / Site-to-Site VPN
RouteServerSubnet /27 /24 /27 Azure Route Server
AzureBastionSubnet /26 /24 /26 Azure Bastion
AzureFirewallSubnet /26 /26 /26 Azure Firewall
AzureFirewallManagementSubnet /26 /16 /26 Azure Firewall Manager
Delegated Services Name min. Size of Subnet Max. Size of Subnet Recommand Size of Subnet Related Azure Services
Microsoft.DBforPostgreSQL/flexibleServers /28 /27 /27 Azure Database for PostgreSQL - Flexible Server
Microsoft.Web/serverFarms /26 /27 /27 Azure App Service
Microsoft.Network/dnsResolvers /28 N/A /28 Azure Private DNS Resolver (inbound)
Microsoft.Network/dnsResolvers /28 N/A /28 Azure Private DNS Resolver (outbound)
Microsoft.AVS/privateClouds /22 /22 /22 Azure VMware Solution
Azure PaaS min. Size of Subnet Max. Size of Subnet Recommand Size of Subnet Dedicated Subnet?
Azure Virtual WAN Hub /24 N/A /24 Yes
Azure Application Gateway /26 (Standard or WAF SKU) N/A /24 (Standard_v2 or WAF_v2 SKU) Yes
Azure AD Domain Services (AADDS) ? N/A ? No
Azure SQL Managed Instance (SQL MI) /27 N/A N/A Yes
App Services (Web Apps, Functions, API Apps) /28 N/A /26 Yes
Azure API Management ? N/A ? Yes
Azure Container Instances (ACI) ? N/A ? Yes
Azure Spring Cloud /28 N/A Depends on Requirement Yes
Azure Red Hat OpenShift Master Subnet /27 /27 /27 Yes
Azure Red Hat OpenShift Worker Subnet /27 /24 /25 Yes


Special Thanks to davidc.net + GitHub Copilot Enterprise

The source code for Azure Edition page has been forked and ported from davidc.net and GitHub Copilot Enterprise for suggestions on modifications to HTML / CSS / Javascript.

Maintainer: Phil Huang ([email protected]), Senior Cloud Solution Architect, Microsoft Taiwan