Description
Calculate fixed-header share of supplied payload-plus-header bits.
Information quantities depend on the logarithm base, event model and symbol accounting. Bits, nats and hartleys are logarithmic units, while source symbols, channel symbols and header bits describe different counting bases. A local mass residual or expansion factor does not estimate entropy, independence or channel capacity from data.
Calculate fixed-header share of supplied payload-plus-header bits.
When to use this tool
Use Coding Overhead Fixed Header Share when you already have payloadBits, fixedHeaderBits and need to calculate fixed-header share of supplied payload-plus-header bits.
How to use the tool and how it works
- Enter payloadBits, fixedHeaderBits. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read totalBits, headerFraction. Use the output convention below.
Require nonnegative safe whole payload/header counts and positive combined size; sum using BigInt and return safe totalBits plus header/(payload+header).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| payloadBits | Payload Bits | Required. Safe integer; minimum 0. |
| fixedHeaderBits | Fixed Header Bits | Required. Safe integer; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| totalBits | Exact payload+header integer sum exported only when safe; must be positive. | Required. Safe integer. |
| headerFraction | Header Fraction | Required. Finite number. |
{
"input": {
"payloadBits": 900,
"fixedHeaderBits": 100
},
"output": {
"totalBits": 1000,
"headerFraction": 0.1
}
}Limitations and assumptions
- Zero payload is allowed with positive header. Unsafe totals are rejected; actual encoding, packet layout and channel efficiency are not inspected.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Evaluate the full probability model, code and payload/header format when studying information or efficiency. Keep symbol and logarithm bases explicit; a unit conversion or one joint-mass reference term is only a local calculation.
References
Similar or alternative tools
- Source Channel Symbol Rate
Calculate channel-symbol rate from a supplied source rate and expansion factor.
- Information Unit One Bit Reference
Convert a supplied bit quantity to nats and hartleys.