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Moving average lab

See exactly what changing the period of a moving average costs you, so you stop treating 50 and 200 as though they were laws of nature.

About 3 min to an answer Free, no sign-up Runs in your browser
Read the lesson: Moving averages
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Runs entirely in your browser — nothing you type is sent anywhere. Educational only, and not investment advice.

How to use this calculator

Each step names a control you will find on screen above.

  1. Period (sessions)

    Drag it from short to long. Watch the line go from hugging price and whipsawing, to smooth and late.

  2. Compare both

    Turn on the comparison to see simple against exponential at the same period. The exponential weights recent sessions more, so it turns sooner and whipsaws more.

  3. Count the false crossovers

    At a short period, count how many times price crosses the line without a real move following. That count is the cost of responsiveness.

  4. Find your own trade-off

    There is no correct period. There is only the trade-off between being early and being wrong, and you have to choose where to sit on it.

Worked example: Twenty sessions against two hundred

Set the period to 20, note the behaviour, then set it to 200 and compare.

What to enter

Period (sessions)
20, then 200
Compare both
On

What it shows you

20-period
Turns within days

many crossovers, most meaningless

200-period
Turns after weeks

few crossovers, each significant

EMA vs SMA at 20
EMA turns 2–3 sessions sooner
The trade-off
Early and often wrong, or late and usually right

Where this is taught

A calculator gives you a number. These explain what the number means and when it misleads you.

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