u Chart Formulas
QI Macros Can Calculate Them For You!
Draw a u Chart using QI Macros
- Select your data.
- Select u chart on QI Macros menu.
- QI Macros will do the math and draw the graph for you.
Go Deeper:
u Charts determine stability of "counted" data (e.g., errors per bill, dents in a car door, etc.) when there can be more than one defect per unit and the sample size varies.
Here is the formula used to calculate a u Chart.
cᵢ = number of nonconformities
nᵢ = sample size
Conforms with ANSI/ASQC B1, B2, B3 1996
NOTE: It is not possible to have negative limits on a u Chart. With that, any calculated value that is below 0 is automatically changed to 0.
Stop Struggling with u Charts!
Start creating your u Charts in just minutes.
Download a free 30-day trial. Get u Charts now!
The u Chart is just one of the tools included in QI Macros SPC Software for Excel.
Why Choose QI Macros Over Other Control Chart Software?
Faster to Learn
and Easier to Use
- Works right in Excel
- Create charts in seconds
- Easy to customize & share charts
- Free Training Anytime
Proven and Trusted
- More than 100,000 users
- In More than 80 countries
- Five Star CNET Rating - Virus free
Affordable
- Only $375 USD
Quantity Discounts Available - No annual subscription fees
- Free technical support
