Azure Private Link Cost Calculator & TCO Guide Price Estimator

A Comprehensive TCO Modeling Guide

The TCO of a Private Link deployment is a composite of fixed infrastructure costs and variable data transfer costs. This guide deconstructs the pricing model, offering strategic insights into cost optimization by showing how architectural choices directly influence your overall bill.

Section 1: Core Infrastructure Costs: The Fixed Baseline

The first step is establishing the non-negotiable, recurring costs for the foundational components. This is your minimum monthly expenditure before any data is transferred.

Endpoint Uptime: The "Always-On" Charge

Each Private Endpoint incurs a fixed hourly charge ($0.01/hr) just for being provisioned, regardless of data flow. This "idle" cost is a frequent source of surprise.

Data Processing: The "Toll Gate" for Traffic

All data passing through an endpoint is subject to a processing fee (starting at $0.01/GB), applied in addition to any other data transfer charges.

Private DNS Zones: The Name Resolution Engine

Private Link relies on DNS. Azure Private DNS Zones are the native, cost-effective solution, with a small monthly hosting fee ($0.50/zone) and a charge per million queries ($0.40/million).

Section 2: The Variable Cost Maze: Data Transfer Patterns

These costs are highly variable and represent the largest potential for both overruns and optimization. The key is understanding the "Peering Exception".

The Critical Insight: Private Link Peering Exception

Standard VNet Peering

Hub VNet ↔ Spoke VNet

$0.01/GB

→

Traffic to Private Endpoint

Hub VNet ↔ Spoke VNet

$0.00 (Waived!)

Official Azure docs state that standard VNet Peering charges are waived for traffic destined for a Private Endpoint. You only pay the endpoint's data processing fee. This makes centralized hub-and-spoke models incredibly cost-effective.

Section 3: Strategic Recommendations for Cost Optimization

Consolidate Endpoints

Leverage the peering exception. Centralize endpoints for shared services in a hub VNet to avoid redundant hourly charges from "endpoint sprawl."
Leverage Data Locality

Minimize cross-region data transfer. It's an order of magnitude more expensive. Co-locate consuming applications and their target PaaS services in the same Azure region whenever possible.
Monitor Programmatically

Use Azure Cost Management and the Retail Prices API to track expenses against your forecast. Turn cost estimation into a continuous governance process.

Section 4: Common Architectural Scenarios & Cost Implications

Let's apply these cost principles to tangible, real-world architectures to see how design choices impact the final bill.

Scenario A: Single-Region Hub-and-Spoke

A classic topology where a central hub VNet hosts a shared Private Endpoint for an Azure Storage account. Two spoke VNets write logs to it. This design is highly cost-effective.

Spoke VNet A

App VM

Hub VNet

Central Private Endpoint

Spoke VNet B

App VM

Fixed Cost: Minimal. Only one endpoint and one DNS zone. (~$7.80/mo).
Data Processing Cost: Based on total logs written (e.g., 700 GB = $7.00).
Peering Cost: $0.00 due to the peering exception.
Result: A lean, predictable, and low-cost model for shared services.

Scenario B: Multi-Region Geo-Distributed

An application deployed across two regions for high availability, with a Private Endpoint in each region for a geo-replicated Cosmos DB. This increases fixed costs but optimizes performance and reduces expensive cross-region traffic.

Region A (East US)

VNet with Local Endpoint

Region B (West Europe)

VNet with Local Endpoint

Fixed Cost: Doubled. Two endpoints and two DNS zones. (~$15.60/mo).
Data Processing Cost: Applied to data processed by each local endpoint.
Peering Cost: Any traffic between regions incurs expensive Global Peering charges.
Result: Higher baseline cost for higher availability. The main goal is to keep traffic local to avoid steep inter-region data transfer fees.

Section 5: Hybrid Connectivity Considerations

When connecting on-premises datacenters to Azure via ExpressRoute or a Site-to-Site VPN, Private Link provides a secure path to PaaS services. It's crucial to understand that Private Link costs are additive in this scenario.

Private Link Costs are an Overlay

You will pay for the Private Endpoint uptime and data processing in addition to your monthly ExpressRoute circuit fees and any data egress charges associated with your plan. Private Link secures the path to the PaaS service, but it does not replace the cost of the underlying hybrid connection.

Section 6: Understanding the TCO Calculator Framework

This interactive tool isn't just a simple form; it's the front-end for a structured cost model built on the principles outlined in this guide. Understanding its components helps you provide more accurate inputs for a more reliable forecast.

Input 1: Infrastructure Quantities

The model begins with your fixed components: the total number of Private Endpoints and Private DNS Zones. These inputs directly determine your baseline monthly cost before any data moves.

Input 2: Data Volumes & Processing

Next, the model requires the total volume of data (in GB) that will be processed by your endpoints, separating inbound and outbound traffic. This, combined with DNS query estimates, calculates the bulk of your variable, usage-based costs.

Input 3: Standard Connectivity Paths

Finally, the model accounts for any standard VNet peering traffic that is not going to a Private Endpoint. This ensures that the peering exception is correctly applied, preventing you from overestimating costs in a hub-and-spoke topology.

Section 7: Beyond Estimation: Continuous Financial Governance

A TCO estimate is a starting point. True FinOps maturity comes from turning that forecast into a continuous governance process. The goal is to monitor, learn, and refine your architecture based on real-world usage and cost data.

Step 1: Track with Azure Cost Management

Regularly use Azure Cost Management + Billing to compare your actual monthly spend against the forecast generated here. Create budgets and alerts to get notified of anomalies or cost overruns, allowing you to investigate and remediate issues quickly.

Step 2: Automate with the Retail Prices API

For advanced FinOps, integrate the Azure Retail Prices API into your CI/CD pipelines. This allows you to programmatically fetch the latest pricing and build "what-if" scenarios, modeling the cost impact of architectural changes before they are deployed to production.