EWMA Volatility

Calculate EWMA Volatility instantly with the exact formula and a worked example. Free online calculator — no signup.

EWMA Volatility

λ (decay)
Last r
σ²_(t−1)
σ²_t
0.0001
σ²_t = λ·σ²_{t−1} + (1−λ)·r²Calculate EWMA Volatility instantly with the exact formula and a worked example. Free online calculator — no signup.
σ²_t
0,0001
σ_t
0,01

More about: EWMA Volatility

What it calculates

The “EWMA Volatility” calculator computes σ²_t from 3 parameters: λ (decay), last r, σ²_(t−1).

Used by investors to estimate returns, project savings, and analyze a portfolio.

Example calculation

With parameters λ (decay) = 0.94, Last r = 0.01, σ²_(t−1) = 0.0001 the result is 0.0001 (σ²_t = λ·σ²_{t−1} + (1−λ)·r²).

How to use

  1. Enter the parameter values — every field above is adjustable with a slider.
  2. The result and related metrics are calculated automatically as you type.
  3. Use the additional metrics shown (if any) where needed.
  4. Copy the result or bookmark the page.

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