How to calculate the cost of video editing?

Question

Video

Tell me please.
How to correctly count the hours when working with video, in order to be honest both for yourself and for the client (for freelancing)
For example, the work on the video itself is elementary, cropping, adding a background, etc. by adding video and saving the video itself:
1. on the one hand - you do nothing while the video is being saved
2 on the other hand - while the video is being saved you cannot do anything, respectively, you lose working hours.
Thank you!

Answer 1

The cost of work is calculated by the man-hours that it took to work (do not count the time when a person does not follow and does not work) plus the depreciation of the hardware used (the cost is divided by the warranty period) and the same for software (if the cost of applications is fixed, then consider the period between major upgrades that require a repurchase or additional payment). By the way, iron can be rented from Amazon - get a clear hourly rate (take spot prices).
Then you add taxes and risks for rework in case of errors that are beyond your control (for example, they turned off the light / Windows decided to update and the calculation stopped, breaking everything, I had to start again), multiplying the probability of this event by the cost of the retry.
And this is only the cost - i.e. exit to zero.