Enter numbers separated by spaces, commas, or new lines. The calculator instantly computes the arithmetic mean, total sum, number count, and how many invalid entries were ignored.
The Average Calculator computes the arithmetic mean of a list of numbers — one of the most fundamental statistical measures in math, science, finance, and everyday life. Simply enter your numbers and instantly get the mean, total, count, and number of ignored inputs. To add up the full total without averaging, try the Sum Calculator; to measure how values changed over time, use the Percentage Change Calculator.
Average (Mean) = Sum of All Values ÷ Count of Values
Find the average of 10, 20, 40, and 80:
Step 1 — Add: 10 + 20 + 40 + 80 = 150 Step 2 — Count: 4 numbers Step 3 — Divide: 150 ÷ 4 = 37.5
1. Average test score. Your four exam scores are 88, 76, 91, and 85:
Sum = 88 + 76 + 91 + 85 = 340 Count = 4 Mean = 340 ÷ 4 = 85
2. Average monthly expense. You spent $420, $385, and $455 on groceries over three months:
Sum = 420 + 385 + 455 = 1,260 Count = 3 Mean = 1,260 ÷ 3 = $420
3. Average with a decimal result. Find the average of 7, 8, and 10:
Sum = 7 + 8 + 10 = 25 Count = 3 Mean = 25 ÷ 3 = 8.33 (rounded to two decimals)
The arithmetic mean works best with symmetric, evenly distributed data. It can be misleading when your dataset contains outliers — extreme values that pull the average far from the typical value. For example, if nine employees earn $40,000 and one earns $400,000, the average salary is $76,000 — far higher than what most employees actually make.
In these cases, the median (middle value when sorted) is often a more representative measure.
Worked example for the dataset 4, 8, 8, 10, 20 (already sorted):
Mean = (4 + 8 + 8 + 10 + 20) ÷ 5 = 50 ÷ 5 = 10 Median = middle value of five = 8 Mode = most frequent value = 8
Here the single large value (20) pulls the mean above the median, a telltale sign that the data is skewed and the median may describe the "typical" value better.
A weighted average assigns different importance (weight) to each value. For example, if a final exam counts 60% of your grade and a quiz counts 40%, the exam carries more influence. The standard arithmetic mean treats all values equally — use a weighted average when some inputs matter more than others.
Weighted Average = (Σ value × weight) ÷ (Σ weight)
Worked example — a course grade where the exam is worth 60% and the quiz 40%, with scores of 90 and 80:
Weighted = (90 × 0.60 + 80 × 0.40) ÷ (0.60 + 0.40)
= (54 + 32) ÷ 1 = 86 The plain arithmetic mean of 90 and 80 would be 85; weighting the exam more heavily raises the result to 86.
| Numbers | Sum | Count | Average |
|---|---|---|---|
| 5, 15 | 20 | 2 | 10 |
| 2, 4, 6 | 12 | 3 | 4 |
| 10, 20, 30, 40 | 100 | 4 | 25 |
| 1, 2, 3, 4, 5 | 15 | 5 | 3 |
| −10, 0, 20 | 10 | 3 | 3.33 |
Add all the numbers together, then divide by the count. For example, the average of 10, 20, and 30 is (10 + 20 + 30) ÷ 3 = 20.
Mean is the arithmetic average (sum ÷ count). Median is the middle value when all numbers are sorted. Mode is the value that appears most often. All three are measures of central tendency but describe a dataset differently.
The mean can be distorted by outliers — extremely high or low values. For example, in income data where a few people earn very high salaries, the median gives a more representative picture of typical earnings. If your data is skewed, consider using the median instead.
A weighted average assigns different importance to each value. For example, if a final exam counts 60% of your grade and a quiz counts 40%, the exam score carries more weight. The standard arithmetic mean treats all values equally.
Yes. Negative numbers are fully supported. For example, the average of -10, 0, and 20 is (-10 + 0 + 20) ÷ 3 = 3.33.
Yes. You can paste numbers separated by commas, spaces, or line breaks — the calculator handles all formats automatically.
Non-numeric inputs are automatically ignored and reported in the 'Ignored' count, so they won't affect your result.
The average of an empty set is undefined — you cannot divide by zero. The calculator will display 0 when no valid numbers are entered.
Multiply each value by its weight, add those products together, then divide by the sum of the weights. For grades of 90 (weight 60%) and 80 (weight 40%): (90 × 0.6 + 80 × 0.4) ÷ (0.6 + 0.4) = (54 + 32) ÷ 1 = 86. A plain average would have given 85.
In everyday use they mean the same thing — the arithmetic mean. Technically 'average' is a broader word that can also refer to the median or mode, but unless stated otherwise, 'average' refers to the arithmetic mean: the sum divided by the count.
If the new number is above the current average, the average rises; if it's below, the average falls; if it equals the average, nothing changes. For example, adding 30 to the set 10, 20 (mean 15) raises the mean to 20, because 30 is above 15.
A running average updates the mean as new data arrives, while a moving average takes the mean of only the most recent fixed number of values — common in stock charts and weather data. Both smooth out short-term fluctuations to reveal a trend.
Keep the average no more precise than your input data. If you averaged whole-dollar amounts, one or two decimals is plenty. Reporting many extra digits implies a precision your measurements don't actually have.
No. Addition is commutative, so the sum — and therefore the mean — is identical no matter what order you enter the numbers in. Sorting only matters when you're finding the median.