Packets Per Second Calculator
Convert a bit rate into packets per second for a given frame size, including preamble and interframe gap.
About Packets Per Second Calculator
Every Ethernet frame carries 20 bytes of overhead the frame size does not include — a 7-byte preamble, a 1-byte start delimiter and a 12-byte interframe gap. Dividing the bit rate by the full on-wire bit count gives the true packet rate. Forwarding hardware and software data planes are rated in packets per second, not bits per second, so small-frame traffic can saturate a device at a fraction of its nominal bandwidth.
Formulas
Packets Per Second
pps = bits per second ÷ (frame bytes × 8), where frame bytes include the 8-byte preamble and 12-byte interframe gap.
- bits per second
- Line rate in bits/s
- frame bytes
- Frame plus 20 bytes of preamble and gap
- pps
- Packets per second
Payload efficiency
payload efficiency = payload bytes ÷ wire bytes
- payload bytes
- Frame minus 14-byte header and 4-byte FCS
- wire bytes
- Everything the link must transmit per frame
Worked example
With the default values below, Packets Per Second Calculator returns Packets Per Second of 81,274. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Throughputminimum 0.1 Mbit/s
- 1,000 Mbit/s
- Ethernet frame sizeaccepts 64–9,022 bytes
- 1,518 bytes
- Preamble + interframe gapaccepts 0–40 bytes
- 20 bytes
Results
- Packets Per Second
- 81,274 pps
- Packets Per Second
- 0.0813 Mpps
- Bits On The Wire Per Frame
- 12,304 bits
- Payload Efficiency
- 97.53%
- Payload Throughput
- 975.29 Mbit/s
Step by step
- 1Values used
- 2Packets Per Second
- 3Payload efficiency
- 4Packets Per Second= 81,274 pps
- 5Packets Per Second= 0.0813 Mpps
- 6Bits On The Wire Per Frame= 12,304 bits
- 7Payload Efficiency= 97.53
- 8Payload Throughput= 975.29 Mbit/s
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Packets Per Second calculated?
pps = bits per second ÷ (frame bytes × 8), where frame bytes include the 8-byte preamble and 12-byte interframe gap. Every Ethernet frame carries 20 bytes of overhead the frame size does not include — a 7-byte preamble, a 1-byte start delimiter and a 12-byte interframe gap. Dividing the bit rate by the full on-wire bit count gives the true packet rate.
Why does Packets Per Second matter?
Forwarding hardware and software data planes are rated in packets per second, not bits per second, so small-frame traffic can saturate a device at a fraction of its nominal bandwidth.
What values do I need to enter?
This calculator takes 3 inputs: Throughput, Ethernet frame size, Preamble + interframe gap. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Why is 64-byte traffic so much harder to forward?
At 64 bytes the wire cost is 84 bytes, so a 10 Gbit/s link carries 14.88 million packets per second — roughly 18× the rate of 1518-byte frames. Per-packet work dominates, so devices hit their pps ceiling long before their bandwidth ceiling.