# How to Calculate Uncertainty in Excel (3 Effective Ways)

### Method 1 – Using the Uncertainty Formula

We have a set of readings of a certain parameter. We are going to determine the uncertainty of the readings.

Steps:

• Choose the C12 cell and enter:
`=AVERAGE(B5:B10)`
• Hit Enter.
• We will get the average of the readings.

• Click on the C13 cell and insert:
`=COUNTA(B5:B10)`
• Press Enter.
• We will get the number of readings.

• Select the C5 cell and insert:
`=B5-\$C\$12`
• Click on Enter.

• Drag the fill handle down to Autofill.

• Click on the D5 cell and insert:
`=C5^2`
• Press the Enter button.
• We will get the square of the previously obtained value.

• Autofill down.

• Choose the F5 cell and enter the following formula:
`=SQRT(SUM(D5:D10)/(C13*(C13-1)))`
• Press Enter.
• We will get the uncertainty value for the dataset.

### Method 2 – Using the STDEV.S Function

We will use the same dataset.

Steps:

• Choose the C12 cell and enter:
`=STDEV.S(C5:C10)`
• Press Enter.
• We will get the Standard Deviation of the dataset.

• Click on the C13 cell and insert”
`=C12/SQRT(COUNTA(C5:C10))`
• Hit Enter.
• We will get the uncertainty of the dataset.

### Method 3 – Calculating Absolute and Percentage Uncertainty

We have the readings of the concentration of a certain chemical. There are 5 readings, and each reading has been taken three times with each test time recorded. We will calculate the absolute and percentage uncertainty of the test times.

Steps:

• Click on the F5 cell and insert the following:
`=AVERAGE(C5:E5)`
• Press the Enter button.
• We will get the average of the 3 test times.

• Autofill the column.

• Choose the G5 cell and insert:
`=E5-D5/2`
• Hit the Enter button.
• We will get the absolute uncertainty of the test times.

• Autofill down.

• Select the H5 cell and enter the following formula:
`=G5/F5`
• Press Enter.
• We will get the percentage uncertainty of the test times.

• Autofill down.

## Related Articles

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