Quality & Six Sigma

Sigma Level Calculator

Enter your DPMO and instantly see where your process sits on the Six Sigma scale — from 1σ all the way to world-class 6σ performance.

Conversion method
Yield = 1 − (DPMO ÷ 1,000,000)
σ = NORMSINV(Yield) + 1.5

Enter your DPMO

Defects Per Million Opportunities — enter a value between 0 and 999,999 Please enter a valid DPMO value between 0 and 999,999.

Sigma reference

691,462
308,538
66,807
6,210
233
3.4
σ

Ready to calculate

Enter your DPMO value on the left and press Calculate to see your Sigma Level.

Your Sigma Level
sigma (σ)
Process Yield
Performance
Position on Six Sigma scale
What this means

How it works

Understanding Sigma Levels

1

The 1.5 Sigma shift

Six Sigma uses a 1.5 sigma shift to account for real-world process drift over time. This is why a 6 Sigma process allows 3.4 DPMO rather than zero.

2

Yield and defects

Yield is the percentage of outputs that are defect-free. A 3 Sigma process has a yield of around 93.3%. A 6 Sigma process achieves 99.9997% yield.

3

What to do next

If your process is below 4 Sigma, a structured DMAIC improvement project is the most reliable path to closing the gap. Use the DPMO Calculator to re-baseline after improvement.