Weighted Mean Calculator
Averages where some values count more than others.
Enter your values
Enter the values you are working with.
Enter the weights you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Weighted mean
- 84.5
- Unweighted mean
- 79.75
- Difference
- 4.75
- Total weight
- 1
- Heaviest item's share
- 40%
Quick answer
A weighted mean multiplies each value by its weight, adds them up and divides by the total weight, so heavier items pull the average toward them.
x̄_w = Σ(wᵢxᵢ) ÷ Σwᵢ
At a glance
| What it does | Averages where some values count more than others. |
|---|---|
| Category | Statistics |
| Inputs needed | Values, Weights |
| Main output | Weighted mean |
| Formula | x̄_w = Σ(wᵢxᵢ) ÷ Σwᵢ |
| Cost | Free — no sign-up, no download |
How to use the Weighted Mean Calculator
- 1Enter each value in order.
- 2Enter the matching weight for each value — percentages, credits or counts all work.
- 3Compare the weighted mean with the plain mean to see how much the weighting matters.
Inputs explained
- Values
- Enter the values you are working with.
- Weights
- Enter the weights you are working with.
Worked example
Using the values the calculator loads with:
Inputs
- Values88, 74, 92, 65
- Weights0.3, 0.2, 0.4, 0.1
Results
- Weighted mean84.5
- Unweighted mean79.75
- Difference4.75
- Total weight1
- Heaviest item's share40%
Frequently asked questions
Do weights have to add to 1?
No. Any positive scale works because the calculator divides by the total weight.
Where is this used?
Course grades, portfolio returns, survey re-weighting, blended prices and any average where sample sizes differ.
What do I need to enter into the Weighted Mean Calculator?
Just 2 values: values, weights. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Weighted Mean Calculator work out the answer?
A weighted mean multiplies each value by its weight, adds them up and divides by the total weight, so heavier items pull the average toward them. It applies the formula x̄_w = Σ(wᵢxᵢ) ÷ Σwᵢ and shows the working so you can check each step by hand.
Is the Weighted Mean Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.