Router Capacity Calculator

Plan stable site connectivity before crews arrive daily. Compare growth, redundancy, and utilization targets quickly. Export results to share with installers and managers today.

Inputs
Enter your jobsite network assumptions
All rates are per-direction and approximate.
Phones, tablets, laptops, scanners, kiosks.
Typical sustained demand during work hours.
Burst factor for meetings, uploads, updates.
Headers, retries, monitoring, and control traffic.
Add headroom for added crews and systems.
Extra capacity for N+1 operation or outages.
Keep routers below this level during peaks.
Higher for web apps and cloud sync.

Optional traffic add-ons
Include streams and tunnels often present on active sites.
Audio calls used by supervisors and teams.
Typical range: 64–100 kbps including overhead.
Cameras, safety monitoring, and perimeter security.
Varies with resolution, compression, and FPS.
Remote design reviews and admin access.
Average tunnel demand during active work.
Environmental sensors, access control, trackers.
Small, but adds up with thousands of nodes.

Security and traffic handling features
These options add processing load and reduce effective throughput.
Adds ~20% processing overhead.
Adds ~30% processing overhead.
Adds ~10% overhead, improves call quality.
Reset
Tip: If your WAN is metered, reduce peak assumptions or add QoS.
Example data
Sample scenario for a mid-size jobsite
Parameter Example Notes
Concurrent Devices80Crews, supervisors, shared kiosks.
Avg Mbps per Device1.5Cloud drawings, messaging, updates.
Peak Multiplier2.0Design sync and reporting bursts.
CCTV Streams × Mbps8 × 31080p H.264 streams.
VPN Users × Mbps5 × 2Remote access for coordination.
Overhead / Growth / Failover15% / 20% / 15%Margins for resiliency and expansion.
Utilization Target70%Stable performance under interference.
Sessions per Device200Modern apps open many connections.
Run the calculator with the defaults to see this scenario’s recommended router capacity and WAN speed.
Formula used
How capacity is estimated
  • Base Throughput (Mbps) = Devices × Avg Mbps per Device × Peak Multiplier
  • Add-ons (Mbps) = VoIP + CCTV + VPN + IoT
  • Raw Total (Mbps) = Base + Add-ons
  • Engineered Load = Raw Total × (1+Overhead) × (1+Feature Impact) × (1+Growth) × (1+Failover)
  • Required Router Capacity = Engineered Load ÷ (Utilization Target)
Why utilization matters
Routers run best with headroom. Keeping peaks under your utilization target reduces jitter, keeps queues short, and improves call and video stability.
How to use
Steps for reliable sizing
  1. Enter the number of devices expected during peak activity.
  2. Set average Mbps per device based on your common workflows.
  3. Adjust peak multiplier for bursty uploads, meetings, and updates.
  4. Add CCTV, VPN, and sensor traffic if those systems share the network.
  5. Enable security features you plan to run on the router.
  6. Review the required router capacity and choose a model with margin.
  7. Export CSV/PDF to share with procurement and installers.

Reminder: This tool estimates throughput and session needs. For full design, also confirm wireless coverage, interference, VLAN segmentation, and WAN provider performance.

Jobsite network demand changes by phase

Early mobilization often runs light traffic, but demand rises fast once trades arrive. A typical mid-size site may jump from 30 devices to 80+ within weeks as foremen add tablets, scanners, and cloud drawing apps. Use the device count and peak multiplier to reflect coordination windows, progress reporting, and software update bursts that stack on top of normal usage.

Create realistic device and application profiles

Average Mbps per device is not a “speed test” number; it is sustained application load. Plan ranges: messaging and light web can sit under 0.5 Mbps, cloud drawings and photo uploads can push 1–3 Mbps, and heavy BIM sync can exceed 5 Mbps for key users. Add VoIP, CCTV, VPN, and sensor traffic so the estimate reflects shared infrastructure, not just office laptops.

Headroom prevents jitter and lost productivity

Overhead, growth reserve, and failover headroom convert raw demand into an engineered load you can trust. Protocol overhead covers retries, headers, monitoring, and control traffic, while growth reserve protects you from added crews and temporary events. Failover headroom supports N+1 behavior when a link degrades. A 70% utilization target keeps queues short and protects real-time calls.

Security features reduce effective throughput

Stateful firewalling, inspection, and shaping consume CPU cycles, especially on encrypted traffic. This calculator models feature impact as added processing overhead: firewall (+20%), IDS/IPS (+30%), and QoS (+10%). Enable the options you will actually run on the router so the required capacity reflects the post-security throughput figure vendors publish. Pair the result with session estimates for NAT sizing.

Use outputs to select routers and links

The required router capacity is the engineered load divided by your utilization target, which yields a practical “minimum rated” number. The recommended WAN speed rounds up for simpler procurement, while the LAN backplane estimate highlights internal traffic needs for camera viewing and file sharing. Choose a router class that meets both Mbps and session tables, then validate with a short pilot during peak hours.

FAQs

How accurate is the Mbps estimate?

It is a planning estimate based on your assumptions. Accuracy improves when you use realistic per-device Mbps, include add-ons, and apply conservative utilization. Validate by monitoring real traffic during a busy shift.

What peak multiplier should I use?

Use 1.5 for steady sites, 2.0 for common jobsite bursts, and 3.0 when large file sync and meetings overlap. If users complain about lag at certain times, increase the multiplier to match that behavior.

Why does enabling IDS/IPS increase capacity needs?

Inspection evaluates more packet content and often more state, which reduces throughput on the same hardware. The calculator adds a processing overhead so the final capacity aligns better with real-world “throughput with security” ratings.

Do I need to include CCTV traffic if cameras are separate?

Only include it when camera video traverses the same router or WAN link as staff traffic. If cameras stay on an isolated local network with a separate uplink, you can set CCTV inputs to zero.

What does the NAT sessions number help with?

It estimates the size of connection tables used by NAT and firewalls. If your router supports high Mbps but low session capacity, web apps and VPN use can still cause drops during peaks.

How do I choose WAN speed from the result?

Start with the recommended WAN speed, then consider provider tiers and redundancy. If you have dual links, ensure each link can carry essential traffic during failover, or increase failover headroom for safer sizing.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.