NETWORK CAPACITY PLANNING TOOL

Bandwidth & Transfer Time Calculator

Estimate transfer time, calculate required bandwidth, size concurrent-user capacity and convert sustained rates into data volume.

bps / Mbps / GbpsGB / GiB / TBConcurrencyEfficiency

Traffic and link parameters

Choose a mode and edit efficiency, utilization and latency assumptions.

Rates use decimal SI units by default. File sizes can use decimal or IEC binary units.

Engineering preset

Project name

File size

Physical link rate

Concurrent transfers

jobs

Payload efficiency

Allowed link utilization

RTT

Setup round trips

RTT

NET

Bandwidth planning result

Payload performance after configured efficiency and utilization limits.

Estimated completion time—

—

Per-transfer payload rate

Aggregate payload rate

Serialization time

Setup delay

Total transferred data

Combined payload factor

Unavailable / overhead share

Concurrent jobs

Payload share of physical link

Core calculation

Payload rate = physical rate × payload efficiency × allowed utilization. Transfer time = file bits ÷ payload rate + setup delay.

METHODOLOGY

Methodology

Bits and bytes

Network speed is expressed in bits per second, while file size is normally expressed in bytes. One byte equals eight bits.

Efficiency and utilization

Protocol efficiency represents the payload fraction. Utilization limits the share of physical link capacity allowed for the workload.

Concurrent transfers

The transfer-time mode assumes concurrent jobs share the available payload rate equally. Scheduling and congestion control can differ.

Latency and setup

Setup delay is modeled as RTT multiplied by setup round trips, then added to serialization time.

Unit references: SI Brochure · NIST SI Units · RFC 6349

FAQ

Frequently asked questions

Why does 100 Mbps not transfer 100 MB every second?

100 Mbps equals 12.5 MB/s before protocol and utilization losses.

Should file size use GB or GiB?

Use GB for decimal storage values and GiB when the source reports IEC binary units.

What efficiency should be used?

Use measured application throughput when available; otherwise start with a preset and retain margin.

Does RTT matter for large transfers?

The tool adds setup delay, while real TCP can also be limited by window growth and recovery.

How is maximum user count calculated?

Available payload bandwidth is divided by engineered per-user bitrate after the burst factor.

Can this replace a traffic-engineering model?

No. Queueing, QoS, retransmissions, traffic distribution and peak-hour behavior still need validation.

PROJECT RECORDS

History

ENGINEERING WORKFLOW

Continue the engineering workflow

Current workflowEnterprise LAN & IP Planning Workflow

Plan addressing, VLAN capacity, packet size, uplinks, optics, access policy and DNS behavior as one LAN design sequence.

Step 5 of 9

PreviousMTU & MSS CalculatorCalculate effective MTU, TCP MSS and fragmentation risk for PPPoE, GRE, VXLAN, MPLS, IPsec and WireGuard.NextSwitch Uplink Bandwidth & Oversubscription CalculatorSize switch uplinks from access ports, utilization, concurrency and redundancy.

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Also used inData Center Network Fabric Planning Workflow