Work out Application Gateway v2 capacity units from connections and throughput, then price the fixed and CU charges.
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.
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 = 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.
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.
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.