Free · Everyday reference models

Playback Duration and Time Difference

Listening time equals source duration divided by a strictly positive speed multiplier. Saved time is source duration minus listening time; extra time is its signed opposite.

Formula & worked example
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How to use this calculator

Enter the known values in the units shown. Results update as you type.
Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
Use the worked example to check the method. Reset restores the starting fields.

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Formula and method

Worked example: total listening time = 1; listening time saved = 1; listening time extra = -1. See the assumptions for units and model limits.

total_listening_time = audiobook_length / playback_speed; listening_time_saved = audiobook_length - total_listening_time; listening_time_extra = total_listening_time-audiobook_length

Worked example

Enter these known values and leave the other values blank.

Media duration: 2 hrs / min
Playback speed: 2 x

New duration: 0:1 hrs / min
Time saved: 0:1 hrs / min

Assumptions and limitations

Listening time equals source duration divided by a strictly positive speed multiplier. Saved time is source duration minus listening time; extra time is its signed opposite.
At speed below one, saved time is negative and extra time is positive. At speed above one the signs reverse. Pauses, advertisements and speed changes are not included.
The worked example supplies2minutes at2× speed, giving1minute listening time. In the hour/minute control,0:02 represents2minutes; a plain scalar denotes the smallest displayed component.

Common questions

What does this model assume?

Listening time equals source duration divided by a strictly positive speed multiplier. Saved time is source duration minus listening time; extra time is its signed opposite.

Can I solve for a different value?

Clear the desired editable unknown and enter sufficient independent known values. Unit selectors preserve quantities; singular or unsupported inverse branches remain incomplete.

References

Reject singular physical denominators and fractional discrete counts using exact isInteger checks.

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