Weighted Average Calculator

Enter values and corresponding weights below. You can also load a simple CSV (value,weight per line).

Decimal places

Controls formatting of the displayed average.

CSV import (client-side only):

Drag & drop CSV here (format: value,weight per line)

Weighted Average – Quick Cheat Sheet

Formula: WA = Σ(w_i·x_i)/Σ(w_i)
Weights scale-invariant: multiplying all weights by the same constant doesn’t change the result.
Percent weights: you may use 20, 50, 30 or 0.2, 0.5, 0.3; both yield the same WA.
Valid rows: each non-empty row must have both a value and a weight. Sum of weights must be > 0.
CSV format: one pair per line: value,weight (e.g., 90,0.3).
Decimals control output formatting only (not internal precision).

Edge cases & notes

Zero weights are allowed; they simply exclude the corresponding value from the average.
If Σ(w) = 0, the calculator will ask for a positive total weight.
All parsing/CSV handling is client-side; files are not uploaded.