Azure Application Gateway Calculator
Work out Application Gateway v2 capacity units from connections and throughput, then price the fixed and CU charges.
Inputs
One compute unit handles about 50 new TLS connections per second with a 2048-bit key.
Standard v2 list rate; WAF v2 is higher.
Capacity Units Needed
45.1CU
Monthly Cost
$442.96
Fixed Gateway Charge
$179.58
Capacity Unit Charge
$263.38
Dimension That Sets Capacity
Throughput at 2.22 Mbps per capacity unit
Headroom Above the Minimum
0.1%
Step by step
Values used
New TLS connections per second = 200 conn/s; Concurrent persistent connections = 6,000 connections; Throughput = 100 Mbps; Minimum capacity units reserved = 2 CU; Fixed gateway rate = 0.2460 USD/hour; Price per capacity unit = 0.0080 USD/CU-hour; Billed hours per month = 730 hours
Azure Application Gateway
capacity units = max(new TLS connections ÷ 50, persistent connections ÷ 2,500, throughput Mbps ÷ 2.22); monthly = fixed rate × 730 + capacity units × CU rate × 730.
Capacity Units Needed
= 45.1 CU
Monthly Cost
= 442.96
Fixed Gateway Charge
= 179.58
Capacity Unit Charge
= 263.38
Dimension That Sets Capacity
= Throughput at 2.22 Mbps per capacity unit
Headroom Above the Minimum
= 0.1
How it works
Application Gateway v2 charges a fixed hourly rate plus capacity units, and a capacity unit is defined by whichever of three dimensions is most stretched: 50 new TLS connections per second, 2,500 persistent connections, or 2.22 Mbps of throughput. Because the maximum wins, a TLS-heavy API with modest bandwidth can need far more capacity units than its Mbps figure suggests. TLS handshakes, not bandwidth, are what usually drive Application Gateway cost, so session reuse and keep-alive tuning translate directly into fewer capacity units; the minimum capacity you reserve is billed continuously, so treat it as a floor for your bill as well as your latency.
Formula
Azure Application Gateway
capacity units = max(new TLS connections ÷ 50, persistent connections ÷ 2,500, throughput Mbps ÷ 2.22); monthly = fixed rate × 730 + capacity units × CU rate × 730.
- capacity unit
- v2 billing unit combining compute, persistent connections and throughput
- 2.22 Mbps
- Throughput one capacity unit sustains
- minimum capacity
- Instances you reserve so the gateway does not scale from cold
Frequently Asked Questions
How is Azure Application Gateway calculated?
capacity units = max(new TLS connections ÷ 50, persistent connections ÷ 2,500, throughput Mbps ÷ 2.22); monthly = fixed rate × 730 + capacity units × CU rate × 730. Application Gateway v2 charges a fixed hourly rate plus capacity units, and a capacity unit is defined by whichever of three dimensions is most stretched: 50 new TLS connections per second, 2,500 persistent connections, or 2.22 Mbps of throughput. Because the maximum wins, a TLS-heavy API with modest bandwidth can need far more capacity units than its Mbps figure suggests.
Why does Azure Application Gateway matter?
TLS handshakes, not bandwidth, are what usually drive Application Gateway cost, so session reuse and keep-alive tuning translate directly into fewer capacity units; the minimum capacity you reserve is billed continuously, so treat it as a floor for your bill as well as your latency.
What values do I need to enter?
This calculator takes 7 inputs: New TLS connections per second, Concurrent persistent connections, Throughput, Minimum capacity units reserved, Fixed gateway rate, Price per capacity unit, Billed hours per month. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
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