How do I calculate an average?
- 1Choose "Average of numbers" or "Weighted average".
- 2Paste or type your numbers, or enter each value with its weight.
- 3Read the average and see exactly how it was worked out.
Average and weighted average formulas
- 01Average (mean) = sum of the numbers ÷ how many numbers there are
- 02Weighted average = Σ(value × weight) ÷ Σ(weights)
The ordinary average shares the total out equally: the marks 72, 85, 90, 64 and 78 add up to 389, and 389 ÷ 5 = 77.8.
A weighted average lets some values count more. If coursework (80) is worth 40% of a grade and the exam (65) is worth 60%, the grade is (80 × 40 + 65 × 60) ÷ (40 + 60) = 71 — not the plain average of 72.5. The same sum gives the average price paid when you buy different quantities at different prices.
Good to know
- Don't average percentages from groups of different sizes — weight each one by its group size.
- One very large or small value pulls the mean a lot; the median is often a fairer "typical" value.
- For a GPA or CGPA use credit hours as the weights, or use the GPA calculator.
Average calculator — common questions
How do I calculate the average of numbers?
Add all the numbers and divide by how many there are. The average of 72, 85, 90, 64 and 78 is 389 ÷ 5 = 77.8.
What is a weighted average?
An average where each value counts according to its weight. Multiply each value by its weight, add those up, and divide by the total of the weights.
What is the difference between mean, median and mode?
The mean is the sum divided by the count. The median is the middle value when the numbers are in order. The mode is the value that appears most often.
How do I average percentages?
Only take a plain average if each percentage comes from a group of the same size. Otherwise use a weighted average with each group's size as the weight.
Sources
- Arithmetic mean and weighted mean — standard statistics
Formulas last reviewed: September 30, 2026 ·How we check our formulas