Ethernet Throughput Calculator
Calculate effective Ethernet throughput and maximum data rate for industrial networks based on bandwidth and protocol overhead.
Ethernet
throughput
bandwidth
PROFINET
EtherNet/IP
packet
overhead
latency
Input values
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Enter values and click Calculate to see results here.
Formula
Effective = (Payload / Packet_size) × Bandwidth
Overhead = Packet_size - Payload
Utilisation = (Data_sent / Time_available) × 100
Worked Example
Given: 100 Mbps Ethernet, 128-byte payload, 64-byte overhead per packet.
Step 1: Packet size = 128 + 64 = 192 bytes = 1536 bits
Step 2: Throughput = (128/192) × 100 Mbps = 66.7 Mbps
Step 3: Max packets/s = 100,000,000 / 1536 = 65,104 pkt/s
With 72-byte minimum inter-frame gap (96 bits), actual max is lower. Always benchmark in production.
Engineering Notes
- Inter-frame gap: Ethernet requires a minimum 96-bit (12-byte) gap between frames. This reduces effective throughput by ~7-10%.
- Preamble + SFD: Each frame starts with 8 bytes (7 preamble + 1 SFD). These are part of the physical layer overhead.
- Jumbo frames: Standard Ethernet MTU is 1500 bytes. Jumbo frames (9000 bytes) improve throughput by reducing per-frame overhead.
- Switch latency: Industrial switches add 1-10 µs per hop. For real-time protocols, this latency must be accounted for.
- Burst traffic: Industrial protocols often send cyclic data at fixed intervals (e.g., 1 ms). Calculate based on your cycle time.
References
- IEEE 802.3 — Ethernet standard
- IEC 61158 — Industrial Ethernet protocols