Every translation project is different. The price calculation is therefore based on the volume, overall complexity and on the required turn-around time. I prefer to calculate translation fees on the basis of the source word count established in MS-WORD. This means, for pure translation work I charge a rate per source word from your original. The advantage of this calculation is obvious: you will know the exact price before you buy.
Proofreading and text editing services are charged at an hourly rate depending on the quality of the work translated by other sources and the level of service required.