Header Overhead Percentage Calculator

Work out header overhead percentage instantly with clear inputs, formula shown and shareable results.

About Header Overhead Percentage Calculator

Header overhead as a share of the frame is what determines goodput, and it is brutal at small frame sizes: a 128-byte frame with 58 bytes of headers wastes 45 percent of the link. That is also where packet rate peaks, so small-frame traffic stresses both bandwidth efficiency and the forwarding engine's packets-per-second ceiling simultaneously.

Formula

Overhead and goodput

overhead share = headers / frame size; goodput = link speed x payload / frame size; frames per second = link bits / (frame bytes x 8)

Worked example

With the default values below, Header Overhead Percentage Calculator returns Header overhead share of 45.31%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Frame sizeaccepts 64–9,216 bytes: 128 bytes
Header and framing bytesaccepts 1–200 bytes: 58 bytes
Link speedminimum 0.001 Mbps: 1,000 Mbps

Results

Header overhead share: 45.31%
Usable goodput: 546.88 Mbps
Payload per frame: 70 bytes
Frames per second at line rate: 976,563 pps

Step by step

1Values used
2Overhead and goodput
3Header overhead share= 45.31
4Usable goodput= 546.88 Mbps
5Payload per frame= 70 bytes
6Frames per second at line rate= 976,563 pps

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 2 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

Why do vendors quote 64-byte frame performance?

Because it is the worst case for packets per second. A device that handles line rate at 64 bytes will handle any traffic mix.

Is goodput the same as throughput?

No. Throughput usually includes headers; goodput counts only application payload. Benchmarks that mix the two are not comparable.