How it works
How Weighted Average Calculator solves the problem
Use this Weighted Average Calculator when you need a weighted average calculator you can trust — clean inputs, transparent steps, zero fluff.
Calculating a weighted average calculator by hand takes five minutes and one stray digit to redo. Weighted Average Calculator runs it in a breath, keeps the working visible, and you get the same number every time you reload.
Getting the arithmetic right first time saves a re-do on paper. Write the formula at the top of the page — then crunch the numbers and the rest of this page explains what the answer means.
Multiply each value by its weight, sum, then divide by total weight. Used for term grades (coursework 40% + exam 60%), portfolio returns and GCSE/A-level averages.
On this page you will see BBC Bitesize, MathsIsFun and ONS treated as first-class terms — each one is linked to the calculators and references that use it, so you can follow the thread without retyping queries into a search bar.
The formula we run is x̄_w = Σ(xᵢ × wᵢ) / Σwᵢ. You'll see each term laid out in the worked example below.
If it helps, jump straight to the Maths hub or compare with the Mean (Average) Calculator and the Median Calculator — those two calcs are the ones readers usually open right after this page.
One scenario, fully unpacked
Put the method down against a real situation and the sequence becomes obvious:
Multiply each value by its weight, sum, then divide by total weight. Used for term grades (coursework 40% + exam 60%), portfolio returns and GCSE/A-level averages.
Every run comes back to x̄_w = Σ(xᵢ × wᵢ) / Σwᵢ — change the inputs, the structure of the answer stays.
Moments this tool earns its keep
Weighted Average Calculator is aimed at people arriving with questions like these:
- "Weighted mean formula"
- "Weighted average example"
- "Grade average with weights"
- "What is weighted average calculator"
- "How to calculate weighted average calculator"
- "Weighted average calculator formula"
Where the number stops being useful
Every tool has an edge where it stops being the right answer. Weighted Average Calculator is no exception:
- For legally binding tax or medical decisions — cross-check with HMRC, NHS or a qualified professional.
- For very large or very small extremes the rounding error outgrows the useful precision.
- When the underlying rate or threshold has changed since the page was last reviewed — always verify with the primary source.
- When the input you have is already a derived figure (net of something) — feeding it in as "gross" will double-subtract.
Traps to steer around
Every time you crunch the numbers for a new scenario, one of these creeps in — it's worth knowing them ahead of time.
- Assuming the UK and US versions of the same unit are interchangeable — they're not.
- Typing a comma where the tool expects a dot (or vice versa).
- Rounding early — particularly painful in percentages and compound growth.
- Ignoring the time window: a 'per year' answer makes no sense with a monthly input.
- Treating the answer as private: screenshots are fine, but the URL always reruns cleanly.
The sources behind the numbers
Where the maths needs an external authority, we cross-check against:
- BBC Bitesize
- MathsIsFun
- ONS
Works well alongside
If this question keeps coming up for you, the same cluster of tools usually comes next:
- Mean (Average) Calculator — Add up your values and divide by how many there are — we show each step.
- Median Calculator — Find the middle value of any data set.
- Standard Deviation Calculator — Measure the spread of a data set with sample or population standard deviation.
How we keep this accurate
Our calculadoras run on pure, unit-tested functions — the same logic lives in the browser and in the CI test suite. When tax rates, thresholds or official figures move, the update lands within 24 hours of the announcement. You can read the editorial policy and corrections policy.
Found an out-of-date number on Weighted Average Calculator or anywhere else in the Maths toolkit? Send it to the editorial desk and we'll patch it. Or browse the full calculadora directory for the next tool you need.