Network Throughput Planner

Planning link capacity with headroom

Network capacity planning is about more than a simple average. Users generate variable traffic with peaks that can be several times higher than their steady-state activity. The peak factor captures those surges so you size for the busy hour rather than the average minute. Protocol overhead accounts for headers, encryption, retries, and management traffic that consume bandwidth without delivering user payload. The combined effect can be significant, especially in high-latency or heavily encrypted environments.

Target utilization is a design choice. Running links at 100 percent during peak hours leads to buffer bloat, packet loss, and latency spikes that users perceive as poor quality. Many teams target 60 to 80 percent utilization to maintain responsiveness and provide room for bursts. This tool divides required demand by the utilization target, effectively reserving headroom so that your peak usage stays within that range.

Uplink and downlink traffic are rarely symmetrical. Video streaming and web browsing are downlink heavy, while backups, file sharing, and VoIP can increase uplink demand. The split input lets you allocate a percentage of the total capacity to uplink and the remainder to downlink. This makes it easy to evaluate asymmetric circuits or to justify a balanced fiber upgrade when uplink demand grows.

The results are reported in both Mbps and Gbps to align with common carrier offerings. Use the total capacity number to select a circuit size, then validate with monitoring data from existing links if available. Remember that Wi-Fi airtime efficiency, ISP contention ratios, and application behavior can all impact real-world performance. This calculator provides a fast, transparent baseline for planning and budgeting, and all math runs locally in your browser for privacy.

Formula

Base demand (Mbps): users × Mbps per user × peak factor

Adjusted demand: base × (1 + overhead/100)

Required capacity: adjusted ÷ (utilization/100)

Uplink/Downlink: capacity × split% and capacity × (1 − split%)

Example calculation

With 250 users at 2 Mbps each and a 1.6 peak factor, base demand is 250 × 2 × 1.6 = 800 Mbps. With 12 percent overhead, demand becomes 800 × 1.12 = 896 Mbps.

At a 70 percent utilization target, required capacity is 896 ÷ 0.7 = 1,280 Mbps or about 1.28 Gbps. If uplink share is 25 percent, uplink is about 320 Mbps and downlink is about 960 Mbps.

FAQs

What does target utilization mean?

It is the maximum percent of link capacity you intend to use during peak periods.

How is protocol overhead applied?

Overhead inflates required capacity to account for headers and non-payload traffic.

What is the peak factor?

The peak factor scales average demand to model busy-hour traffic spikes.

Does this include Wi-Fi efficiency?

No. Wi-Fi airtime and contention should be modeled separately.

Is this private?

Yes. All calculations run locally.

How it works

This tool combines per-user demand, peak factor, overhead, and utilization targets to estimate required link capacity.

Disclaimer

Network capacity estimates depend on traffic patterns and application behavior. Validate with monitoring and vendor guidance.