How to use this running average calculator
See how the average changes after every observation in an ordered sequence. Enter values in the order they occurred. A cumulative table shows each value, the running total, and the average up to that point, with a chart of the same calculated results.
- Enter the observation in order values in the labeled fields, using consistent units.
- Load the example to inspect the expected format, then replace it with your own values.
- Select Calculate and check the result alongside its working. Reset starts a fresh calculation.
Running Average formula
Running mean at k = sum of the first k values ÷ k
A running average keeps every earlier observation. A moving average uses only a selected recent window, so it is a different calculation. Reordering the inputs changes intermediate running averages but not the final mean.
Follow the numbers
For 10, 20, and 30, running totals are 10, 30, and 60; running averages are 10, 15, and 20.
Load the example above to inspect the entries, then change one value and calculate again. The result follows your selected method. Display rounding changes how the answer is shown; it does not change the underlying observations or weights.
What to check before using the result
For readability, tables and charts display at most 100 sampled rows for long sequences. All entered values remain included in the calculation.
Keep enough precision in the source values for your task. A result calculated from rounded summaries can only be as precise as those summaries. If a number was mistyped or an observation is missing, correct the inputs and calculate again before copying or exporting the answer.
Choose a related calculator
Common mistakes to avoid
- Confusing a blank with zero. A real zero is an observation. Missing information is not automatically zero.
- Mixing incompatible scales. Use consistent units, or normalize values before combining them.
- Rounding too early. Keep the original values and round at the result stage.
- Using the wrong weighting. For readability, tables and charts display at most 100 sampled rows for long sequences. All entered values remain included in the calculation.
Frequently asked questions
What formula does this calculator use?
Running mean at k = sum of the first k values ÷ k. For 10, 20, and 30, running totals are 10, 30, and 60; running averages are 10, 15, and 20.
What should I check about the method?
For readability, tables and charts display at most 100 sampled rows for long sequences. All entered values remain included in the calculation.
How many entries can I use?
Paste up to 10,000 values, or use up to 100 individual rows when the chosen input method supports them. Numbers must be finite and no greater than 1 trillion in magnitude. Group and old-count inputs have additional whole-number requirements.
Are the displayed decimals exact?
The calculation uses standard floating-point numbers and compensated addition. Results are rounded only for display. Very small values use scientific notation so they do not silently appear as zero. Select the display precision you need, while respecting the accuracy of your original data.
Are my entries saved or sent anywhere?
The calculator performs its arithmetic in your browser. It does not automatically store entries or send them to a server. Copy, print, and CSV actions happen only when you choose them.
Read our calculation methodology for supported precision, validation, and assumptions.