Moving Average Calculator
Compute simple (SMA), exponential (EMA), and weighted (WMA) moving averages over any number series. Choose the window size and get the smoothed value at each point — all in your browser, nothing uploaded.
About this tool
The moving average calculator smooths a number series by averaging values over a sliding look-back window. It computes the three most widely used moving averages side by side:
- Simple moving average (SMA) — the unweighted mean of the last period values. Every point in the window counts equally.
- Exponential moving average (EMA) — a weighted average that reacts faster to
recent values. It uses the smoothing factor
k = 2 / (period + 1)and is seeded with the simple mean of the first window, the standard finance convention. - Weighted moving average (WMA) — uses linear weights
1, 2, …, periodso the most recent value carries the most weight and the oldest the least.
Paste your series (separated by spaces, commas, semicolons, or newlines), choose a
period (the window size), and the tool returns the SMA and EMA at every point.
During the warm-up region — before enough points are available to fill the
window — the value is reported as null.
How to use it
- Paste or type your numbers into the Number series box.
- Set the Period — e.g.
3for a 3-point average,20for a 20-day average. - Read off the SMA and EMA arrays, one entry per input point.
Common uses
- Smoothing stock or crypto price data for technical analysis.
- Filtering noise out of sensor readings or metrics.
- Spotting trends in sales, traffic, or any sequential data.
Privacy
Everything runs locally in your browser via WebAssembly. Your data is never uploaded to a server.
FAQ
Why do the arrays start with null values?
A moving average needs a full window before it can produce a value, so the
first period − 1 entries are null for all three averages. The EMA's first
real value (at index period − 1) is seeded with the simple mean of that
first window, then advanced with the EMA recurrence from there.
SMA, EMA, or WMA — which one should I look at?
SMA weighs every point in the window equally, so it's the smoothest but the
slowest to react. EMA (smoothing factor k = 2/(period + 1)) responds faster
to recent moves — it's the usual choice in trading. WMA sits in between,
weighting the window linearly 1, 2, …, period so the newest value counts
most. The tool returns all three so you can compare directly.
What are the size limits?
Up to 100,000 data points and a period of up to 10,000. The period must also be no larger than the number of points you paste — a 20-point average of a 10-value series is rejected with an error rather than padded.
How precise are the results?
Each value is rounded to 6 decimal places before it's returned. That's enough for price and sensor data while keeping the output readable; the underlying computation itself runs in full 64-bit floating point.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool moving-average "10, 12, 13, 12, 15, 16, 14, 18, 20, 19"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/moving-average/?series=10%2C%2012%2C%2013%2C%2012%2C%2015%2C%2016%2C%2014%2C%2018%2C%2020%2C%2019&period=3Machine-readable descriptor: tool.json — title + parameters JSON Schema for agents.