Average Calculator
Calculate the arithmetic mean by entering the sum and number of values.
Formulas
Arithmetic mean. Pure arithmetic, no jurisdiction dependency.
average = sum / count
Assumptions and limitations
Scope
Calculate the simple arithmetic mean (all elements have the same weight). Applicable to homogeneous data on a ratio scale. For asymmetric distributions or with outliers, also consider the median.
Assumptions
- Arithmetic mean. Pure arithmetic, no jurisdiction dependency.
Limitations
- Non rappresentativa in presenza di outlier estremi
- Non adatta a dati categoriali o ordinali
- Calcola solo la media semplice: non supporta media ponderata (dove ogni valore ha un peso diverso)
- Non indica la dispersione dei dati: due gruppi con media uguale possono essere molto diversi
Validation
Approach: Validated by verifying the declared formula and plausibility checks (range, units, edge cases).
Examples
School grades
- Somma 350 / 5 voti = media 70. Se i voti sono distribuiti uniformemente (60, 65, 70, 75, 80) la media è perfettamente rappresentativa.
Income with outliers
- Somma €1.700 / 5 persone = media €340. Ma se i redditi sono 100, 100, 100, 100, 1300: la media di 340 non rappresenta nessuno dei cinque. La mediana (100) sarebbe più informativa.
Frequently asked questions
When is the average not the right value to use?
When the data contains extreme outliers. E.g.: if four people earn €1,000/month and one earns €50,000, the average is €10,800 but doesn't represent any of the five. In these cases use the median (the central value, after sorting the data).
Can I calculate the average of any set of numbers?
Yes: add up all the values and enter the total as Sum, then enter how many values you have as Number. E.g.: 5 measurements (12, 15, 10, 18, 20) → Sum=75, Number=5 → average=15.
Can I calculate a weighted average with this tool?
No. This calculator computes the simple arithmetic mean, where all values have the same weight. For weighted averages (e.g. university grade average with different credits), multiply each value by its weight, sum the products, and divide by the sum of weights.