85, 40 or 95, 60 → 91).Note: Weights are relative scale weights and do not need to sum to 100.
- 1Enter one value-weight pair per line. Use the format: value, weight (e.g., "85, 40").
- 2You can also separate the value and weight with "@" or ":" (e.g., "85 @ 40" or "85 : 40").
- 3The calculator computes the weighted average, the sum of all (value × weight) products, and the total weight.
A weighted average assigns different levels of importance (weights) to each value in a dataset. Unlike the arithmetic mean, which treats every value equally, a weighted average multiplies each value by its corresponding weight before averaging. This is essential when some data points matter more than others — such as course grades with different credit hours or portfolio returns with different investment amounts.
Multiply each value by its weight, sum the products, and divide by the total weight.
Weighted Average = Σ(valueᵢ × weightᵢ) / Σ(weightᵢ)Two exams: 85 (weight 40) and 95 (weight 60).
(85 × 40 + 95 × 60) / (40 + 60) = (3400 + 5700) / 100 = 91Homework: 90, weight 20 | Midterm: 78, weight 30 | Final: 85, weight 50 → (90×20 + 78×30 + 85×50) / (20+30+50)Weighted sum = 85×40 + 95×60 = 3400 + 5700 = 9100; Total weight = 100; Average = 9100 / 100Weighted sum = 4 + 9 + 60 = 73; Total weight = 5; Average = 73 / 5- Weights are relative, not absolute. Weights of 1, 2, 3 produce the same result as weights of 10, 20, 30 — only the ratios matter.
- Negative weights are not allowed. The calculator will display an error if a negative weight is entered.
- If all weights are equal, the weighted average equals the arithmetic mean.
- This calculator is different from the Mean Calculator. The Mean Calculator computes the arithmetic mean of a flat list of numbers (all equally weighted). This calculator handles value-weight pairs.
Do weights need to add up to 100?
No. Weights are relative proportions. The calculator divides by the actual sum of all weights, regardless of what they total.
How is this different from the Mean Calculator?
The Mean Calculator computes the arithmetic mean of a simple list of numbers where every value counts equally. The Weighted Average Calculator lets you assign different importance (weight) to each value.
Do the weights need to add up to 100?
No. The calculator divides the weighted sum by the actual total of the weights, so any consistent scale works.
How is this different from the Mean Calculator?
The Mean Calculator averages a plain list of numbers with equal importance. This one multiplies each value by its own weight before averaging.