Weighted average calculator

Paste your values with their weights, one per line. We give you the weighted average, the simple one, and how much each item contributes.

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Your figures

Format: name (optional), value and weight. Leave the weight out and it counts as 1.

Result

Weighted average 7.76
How much each item weighs in the average
Matemáticas: 6 (35,3 %)Lengua: 4 (23,5 %)Historia: 4 (23,5 %)Inglés: 3 (17,6 %)TOTAL17
  • Matemáticas635,3 %
  • Lengua423,5 %
  • Historia423,5 %
  • Inglés317,6 %
Simple average (no weights)
7.75
Median
7.75
Items
4
Sum of the weights
17.00
Highest value
9.00
Lowest value
6.50

What each item contributes

What each item contributes
ItemValueWeightRelative weightContributes
Matemáticas 8.50 6.00 35.3% 3.000
Lengua 6.50 4.00 23.5% 1.529
Historia 7.00 4.00 23.5% 1.647
Inglés 9.00 3.00 17.6% 1.588

What we assume

  • The last number on each line is the weight and the one before it is the value. With a single number, the weight is 1.
  • Lines with no numbers at all are ignored, and we tell you which ones.
  • For a course average, the weight is the credits of each module.
  • Institutions have their own rules about resits and transferred credits: this is the arithmetic, not your regulations.

How it is calculated

A weighted average multiplies each value by its weight, adds the results, and divides by the sum of the weights:

average = sum(value x weight) / sum(weight)

It is the average you want when the items are not worth the same. The classic case is a degree average: a 12-credit module counts four times as much as a 3-credit one.

Why we also show the simple average

Comparing the two tells you at a glance how much the weights are moving you. If your weighted average is lower than the simple one, you did worse precisely in the things that count most.

Formats it accepts

You can paste it almost however you like. These three lines are all understood the same way:

8.5 6 · Maths 8.5 6 · Maths; 8.5; 6

An example

Four modules at 8.5, 6.5, 7 and 9, weighted by 6, 4, 4 and 3 credits, average 7.68. The simple average is 7.75: the weights pull it down slightly, because the best mark is in the smallest module.

Frequently asked questions

What do I use as the weight for a course average?

The credits of each module. That is exactly what credits are for: they say how much each module counts.

What if I leave the weight out?

That line counts with a weight of 1. Mixing weighted and unweighted lines works, but check it is what you meant.

Why is the median shown as well?

Because an average hides outliers. If your median is far from your average, one very high or very low value is doing a lot of the work.

Keep calculating

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Updated on 2026-08-26. Calculations run in your browser; nothing you type is sent to a server.

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