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About Weighted Average Calculator

In life and math, not everything is equal. A "Simple Average" (Mean) treats every number as having the same importance. A Weighted Average assigns a "weight" or importance level to each number. This concept is foundational in grading, finance, and statistical analysis.

Real World Applications

  • Course Grading: A syllabus might say: "Homework 20%, Quizzes 30%, Final Exam 50%". You cannot just average the scores; you must apply the weights. A 100 on Homework is less valuable than a 100 on the Final.
  • Stock Portfolios: If you own $1000 of Apple stock and $100 of Penny Stocks, your portfolio return is a weighted average. A 10% drop in Apple hurts far more than a 10% drop in the penny stock.
  • Product Reviews: Some sites weight recent reviews higher than old ones to give a current score.

The Calculation

Weighted Mean = Sum(Value * Weight) / Sum(Weights). This ensures the result reflects the true "center of gravity" of the data.

How to Use

Enter pairs of values and their weights (e.g., Score: 90, Weight: 0.5). The weights can be percentages (0-100) or decimals (0-1), as long as you are consistent.