Calculator Inputs
Enter traffic, security, and infrastructure values to evaluate firewall health, capacity posture, and anomaly pressure in one pass.
Formula Used
Total Traffic (GB) = Inbound Traffic + Outbound Traffic
Average Throughput (Mbps) = (Total Traffic Bytes × 8) ÷ Observation Seconds ÷ 1,000,000
Packets Per Second = Total Packets ÷ Observation Seconds
Average Packet Size = Total Traffic Bytes ÷ Total Packets
Average Session Size (MB) = Total Traffic (GB) × 1024 ÷ Effective Session Base
Allow Rate = Allowed Sessions ÷ Effective Session Base × 100
Block Rate = Blocked Sessions ÷ Effective Session Base × 100
Failure Rate = Failed Connections ÷ Effective Session Base × 100
Retransmission Rate = Retransmissions ÷ Total Packets × 100
Threat Density per 1,000 Sessions = Threat Hits ÷ Effective Session Base × 1000
Capacity Utilization = Average Throughput ÷ Firewall Capacity × 100
Projected Throughput = Average Throughput × (1 + Growth %)
Projected Safe Headroom = Firewall Capacity × Safe Utilization % − Projected Throughput
Health Score uses weighted penalties from latency, utilization, resource pressure, threats, retransmissions, failures, and abnormal blocking behavior.
Anomaly Score combines block rate, failure rate, threat density, scan density, retransmissions, latency stress, and safe-capacity pressure on a 0–100 scale.
How to Use This Calculator
- Choose a clear observation window such as fifteen minutes, one hour, or one day.
- Enter session counts from your firewall dashboard, SIEM, or log export.
- Add inbound and outbound traffic totals for the same period.
- Provide packet count, retransmissions, threat hits, and port scan alerts.
- Enter current CPU, memory, latency, rated capacity, and safe planning threshold.
- Include expected growth if you want projected headroom and future utilization.
- Click Analyze Firewall Traffic to place results above the form.
- Download the summary as CSV or PDF for audit notes, capacity reviews, or incident follow-up.
Example Data Table
| Scenario | Total Sessions | Inbound GB | Outbound GB | Threat Hits | Latency ms | Capacity Mbps | Comment |
|---|---|---|---|---|---|---|---|
| Normal Office Hour | 85,000 | 120 | 96 | 110 | 4.9 | 1500 | Healthy mix of business traffic with low inspection delay. |
| Peak Remote Access | 160,000 | 355 | 280 | 540 | 8.1 | 1800 | Higher encrypted traffic raises utilization and latency pressure. |
| Attack Spike | 240,000 | 440 | 330 | 3,400 | 16.8 | 1800 | Reconnaissance and malicious bursts demand urgent rule review. |
Use example values to compare typical performance, capacity stress, and hostile traffic behavior.
FAQs
1. What does this firewall traffic analyzer measure?
It estimates throughput, capacity utilization, allow and block rates, retransmission pressure, threat density, projected headroom, and composite health and anomaly scores from traffic and security activity inputs.
2. Why is projected headroom important?
Projected headroom shows how much safe performance margin remains after expected growth. It helps you decide whether current hardware, policies, or inspection profiles can support upcoming demand.
3. What is the effective session base?
The calculator uses the larger of total sessions or the sum of allowed, blocked, and failed connections. This prevents distorted percentages when category counts exceed the original total.
4. How should I choose the observation window?
Pick a period that matches the decision you are making. Use shorter windows for incident spikes and longer windows for planning, baselining, or reporting normal production behavior.
5. Does a high block rate always mean a problem?
Not always. A high block rate may reflect strong policy enforcement during attacks. It becomes more concerning when combined with rising latency, failures, retransmissions, or exhausted capacity headroom.
6. Can I use this for capacity planning?
Yes. Enter the firewall’s rated throughput, safe utilization target, and expected traffic growth. The calculator then estimates future utilization and whether your safe operating margin remains acceptable.
7. What affects the anomaly score most?
Threat density, scan activity, failure rate, retransmissions, elevated latency, and traffic beyond the safe capacity limit all push the anomaly score upward more aggressively.
8. Is this a replacement for packet capture or SIEM analysis?
No. It is a decision-support summary tool. Use it alongside firewall logs, packet captures, SIEM dashboards, and vendor-specific monitoring for full operational investigation.