Do not underestimate the time it takes to transcribe and translate an audio or a video file, especially if you also have to provide start and end times and when there are more than two participants. Of course, the quality of the audio/video plays a significant part, but for the purpose of this calculation, let’s assume that the quality is fairly good and the number of speakers is between two and three.
Based on my experience, 60 minutes of an audio can take 5-7 hours just to transcribe. This includes providing cues and listing for proof.
Then we have to determine the number of words in 60 minutes of an audio, which can be quite a number. It is assumed that we speak around 110-150 words per minute. So this times 60 minutes equals 6600-9000 words.
Now the only thing left is to think of your hourly rate and how much you charge for a translation of 1000 words. For 60 minutes, it will be 5-7 hours to transcribe and 6600-9000 words to translate. Assuming that you work 8 hours, 5 days a week and translate 2000 words per day, our project can take between 4-6 days to complete. So we can roughly assume it’s a job for a week.
Please note that when the quality of an audio/video is poor and there is a greater number of speakers, it will take you much more to transcribe it, as you will have to make frequent pauses or you often will have to “rewind” the audio.
Before agreeing on a rate, ask for a sample file to listen to. Only by knowing your source materials, you can provide a quote that will accurately reflect the effort you have to put in.