Everyday arithmetic

Weighted average calculator

Multiply each value by its corresponding weight, add the products, then divide by the sum of the weights.

Your numbers

Use the units shown. Results update as you change valid inputs.

YOUR RESULT

Multiply each value by its corresponding weight, add the products, then divide by the sum of the weights.

THE NUMBERS, EXPLAINED

How to use this calculator.

Multiply each value by its corresponding weight, add the products, then divide by the sum of the weights.

Start with your inputs

Enter values, weights. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.

InputExample value
Values10,20
Weights1,3

A worked example

With the example inputs above, weighted mean is 17.5. Change the inputs to explore your own scenario.

All results for the example inputs above
ResultExample answer
Weighted mean17.5

How this is calculated

Weighted mean

Multiply each value in a by the corresponding weight in b, add those products, then divide by sum(b).

Symbols and units
a
Values
b
Weights

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Calculation steps and notation

sum(list) adds all entries in the list.

Assumptions and limits

Multiply each value by its corresponding weight, add the products, then divide by the sum of the weights.

Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.

Questions about this tool

What does the result tell me?

Weighted mean. The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.

Why might another calculator differ?

Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Multiply each value by its corresponding weight, add the products, then divide by the sum of the weights.

Are my inputs stored or sent to AI?

Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.

Further reading

OpenStax: Prealgebra ↗

Background reading; this does not imply endorsement or independent review of SumFizz.

Review status

Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.

Read the quality report →