A control limit marks an expected process boundary based on a center and spread.
Upper Control Limit Calculator
Form
Results
Upper limit
0
Lower limit
0
Table of Contents
1
What is Upper Control Limit?
2
How to Use This Calculator
- Enter or select Control mean, Control standard deviation, Control limit you want to evaluate.
- Check the unit beside each measurement. For a percentage or rate, use the scale and time period stated in the form.
- Choose Calculate, then compare the output with the formula and example below. If you change a value or option, calculate again to update the result.
3
Formula Used
UCL=mean+kσ; LCL=mean−kσ
4
Variables Explained
| Input | What it means |
|---|---|
| Control mean | The arithmetic average or stated population mean used as a reference. |
| Control standard deviation | The spread of individual observations around their mean, in the data’s original units. |
| Control limit you want to evaluate | Use the measured or stated value for this item, with the unit or category shown beside the field. |
5
Worked Example
Mean 20, standard deviation 2 and k=3 give limits 14 and 26.
6
Why Use This Calculator?
Flag unusual process behavior relative to a stated center and spread.
7
Common Mistakes
- Control limits describe process behavior; specification limits describe what a customer or design requires.
8
Frequently Asked Questions
Does a calculated statistic prove a conclusion?
A statistic describes the supplied data under stated assumptions. Sampling design, missing observations and the suitability of the model still determine what can reasonably be concluded.
Should I include every observation?
Use the observations required by your study design and state any exclusion rule. Removing values only because they change the answer can bias the analysis.
9
Sources & References
Mini Calculator provides online calculators for multiple niches including mathematical, financial, Health, informative, Chemistry, physics, statistics, and conversions. You can use any calculator for free without any limits.