Average Formula Mass
Sum molecular formula mass from caller-supplied average atomic weights.
Description
Average formula mass sums caller-supplied atomic weights and counts.
Average formula mass sums caller-supplied atomic weights and counts. Unlike monoisotopic mass, the weight basis can represent an isotope-average composition.1
Sum molecular formula mass from caller-supplied average atomic weights.
When to use Average Formula Mass
Use this tool to sum molecular formula mass from caller-supplied average atomic weights.
Prepare the measured profile, formula counts, upstream model outputs or caller-defined reference criteria requested. Keep paired entries aligned and units, sample basis and preprocessing consistent.
How to use Average Formula Mass and understand its results
- Prepare the measured profile, formula counts, upstream model outputs or caller-defined reference criteria requested. Keep paired entries aligned and units, sample basis and preprocessing consistent.
- Enter elementSymbols, atomCounts, averageAtomicWeights using the field table and calculation rules, then run the tool.
- Read averageFormulaMass, atomTotal. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| elementSymbols | Element symbols | list of string | Required |
| atomCounts | Atom counts | list of number | Required |
| averageAtomicWeights | Average atomic weights | list of number | Required |
Enter nonempty aligned symbols, nonnegative safe integer counts and positive weights. All-zero counts are accepted. Return mass and total atoms.
mass=Σcount_i×weight_i; atoms=Σcount_i Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| averageFormulaMass | Average formula mass | number |
| atomTotal | Atom total | number |
{
"input": {
"elementSymbols": [
"C",
"H",
"O"
],
"atomCounts": [
1,
4,
1
],
"averageAtomicWeights": [
12,
1,
16
]
},
"output": {
"averageFormulaMass": 32,
"atomTotal": 6
}
}Limitations and assumptions
Symbols are labels, without element validation or uniqueness checks. Atomic weights and their isotope basis must be supplied correctly.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Monoisotopic Formula Mass: Sum neutral monoisotopic mass from C/H/N/O/S/P atomic compositions. For a complementary task, use Adduct MZ: Calculate adduct ion m/z from neutral mass, injected mass shift, and charge.
References
-
Average Formula Mass — tool.io
Similar or alternative tools
- Monoisotopic Formula Mass
Sum neutral monoisotopic mass from C/H/N/O/S/P atomic compositions.
- Adduct MZ
Calculate adduct ion m/z from neutral mass, injected mass shift, and charge.