Standard Deviation (SD) Calculator from Reference Range

Determine the Standard Deviation and Mean from the low and high limits of the acceptable or reference ranges.

Please click here if you would like to calculate the standard deviation using a given set of data points.

Formula:

Mean = (Low Limit + High Limit) /2
Standard Deviation = (Mean – Low Limit) / 2
**For example, if your reference range is 200-400 mg/dl, then your lower limit is 200 and your high limit is 400**

Principle:

Mean is simply the average between the low and high limit of the acceptable range. To achieve a confidence limit of 95%, the low and high limits of the reference range is calculated using +/- 2SD. Hence, SD is equals to half of the difference between the mean and the low limit or high limit.

Please check out our list of calculators for Laboratory Statistics:

• Standard Deviation Calculator from Reference Range
• Standard Deviation Calculator using Data Points
• Calibration Verification and Linearity
• Method Validation and Correlation