NGFW Sizing Calculator 2025 | Compare 10 Next-Gen Firewalls

What is NGFW and Why Sizing Matters

Next-Generation Firewall (NGFW) goes beyond traditional port/protocol inspection to provide deep packet inspection, application awareness, intrusion prevention (IPS), SSL decryption, and advanced threat protection. NGFWs are the cornerstone of network security, protecting perimeter and internal zones.

🔥 Why NGFW Sizing is Critical

Undersized firewalls create network bottlenecks and security blind spots. Oversized appliances waste $50K-500K. Our calculator helps you size based on actual throughput requirements including SSL inspection overhead.

💰 Pricing Models Explained

NGFW vendors charge based on throughput (Gbps) plus subscription services (threat intelligence, URL filtering, sandboxing). We normalize all pricing including essential security subscriptions for apples-to-apples comparison.

📊 Real Production Data

Our sizing comes from 300+ enterprise NGFW deployments. We account for SSL inspection (reduces throughput 40-60%), active-active clustering, and real-world traffic patterns.

Key Factors in NGFW Sizing

Throughput Requirements: Total bandwidth needs. Typical: Branch (1-5 Gbps), Campus (10-20 Gbps), Data Center (40-100 Gbps), Service Provider (100+ Gbps)
SSL Inspection Impact: Decrypting/re-encrypting SSL traffic reduces throughput by 40-60%. If 80% of traffic is HTTPS, a 10 Gbps firewall becomes 4-6 Gbps effective.
Security Features: More features = more processing. IPS + App Control + SSL Inspection + Sandboxing can reduce throughput to 20-30% of firewall rating.
High Availability: Active-active clustering doubles hardware costs but provides redundancy and load balancing.
Subscription Services: Threat prevention subscriptions cost 30-50% of hardware annually. Budget for 3-5 year lifecycle.

Common NGFW Sizing Mistakes to Avoid

❌ Mistake #1: Using firewall spec sheet throughput. Vendors rate with firewall mode only. Enable IPS + SSL inspection and actual throughput drops to 20-40% of rated speed.

❌ Mistake #2: Ignoring growth. Network traffic grows 25-40% annually. Plan for 3-year capacity or you'll replace in 18 months.

❌ Mistake #3: Forgetting subscription renewals. Subscriptions cost 30-50% of hardware per year. A $50K firewall costs $200K over 5 years with subscriptions.

❌ Mistake #4: Single firewall deployment. No HA = single point of failure. Budget for active-active clustering from day one.

Interactive NGFW Sizing Calculator

Adjust the sliders below to match your environment. Get instant sizing recommendations and vendor-specific pricing.

📝 Your Network Profile

Required Throughput (Gbps) 10 Gbps

1 Branch (5) Campus (20) DC (100) 200

💡 Total bandwidth with SSL inspection enabled (reduces rated throughput by 50%)

Security Feature Set

💡 More features = more processing overhead but better security

Deployment Model

💡 Hardware offers best performance; virtual provides flexibility

Ready to Calculate

Adjust the parameters on the left and click Calculate to see your personalized NGFW sizing recommendations and vendor comparison.

NGFW Sizing Calculator & Vendor Comparison 2025