Quick answer
Add the durations in seconds, then divide by the number of measurements. Convert the mean back to mixed units and round once if needed.
Step by step
- Make one row per measurement. Mark missing values separately from measured zero values.
- Convert each included value to seconds and add. Divide by the number of included rows.
- Convert back to minutes and seconds. If you combine averages from different-sized groups, weight each mean by its original count or add the original totals first.
Worked examples
Average three readings
1:15, 1:45 and 2:00 (minutes:seconds) are 75, 105 and 120 seconds. Their total is 300 seconds, so the mean is 100 seconds or 1:40.
Combine groups correctly
A mean of 2 minutes from two recordings and a mean of 5 minutes from one recording gives (2 × 2 + 5 × 1) ÷ 3 = 3 minutes.
What to check
The mean should fall between the shortest and longest input. Use the division guide when splitting one total into equal blocks.
Related guides
Sources
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