Chemistry

Average Atomic Mass

Weighted average of isotope masses.

Formula

Formula
Σ (massi · abundancei)

Variables

SymbolDefinitionType & rangeUnitsRole
massᵢ isotope masses computed result result
abundanceᵢ fractional abundances computed result result

Try it yourself

Interactive calculator
comma or space separated numbers
comma or space separated numbers
Result

Worked examples

Example 1
Givenisotope masses = 34.969, 36.966, abundances = 0.7577, 0.2423
Result35.4528731
Example 2
Givenisotope masses = 10.013, 11.009, abundances = 0.199, 0.801
Result10.810796