Average Atomic Mass Calculator
Weighted average atomic mass of an element from the isotope masses and their abundances.
Compare Your Options And Get Clear Answers
Weighted average atomic mass of an element from the isotope masses and their abundances.
Average Atomic Mass Estimator
Enter your numbers below for an instant estimate.
How It Works
Key concepts behind this calculator
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Average Quick Guide
Typical values for reference.
| Mass 1 | Abundance 1 % | Mass 2 | Average u |
|---|---|---|---|
| 34.969 | 90 | 36.966 | 35.169 u |
| 34.969 | 75.78 | 36.966 | 35.453 u |
| 34.969 | 50 | 36.966 | 35.968 u |
| 34.969 | 25 | 36.966 | 36.467 u |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Average Atomic Mass Calculator FAQ
Answers to common questions about this calculator.
Multiply each isotope mass by its fractional abundance and add.
It is a weighted average of isotopes.
Average mass = sum of isotope mass x abundance fraction.
It is an estimate based on the inputs you enter. Check real quotes, labels or official guidance for important decisions.