The Total score is out of 1600 marks (Verbal=800 & Quantitative=800), Analytical Writing Assessment (Essays) is scaled from 0 - 6.
The score report includes of:

• a verbal score reported on a 200-800 score scale, in 10-point increments
• a quantitative score reported on a 200-800 score scale, in 10-point increments, and
• an analytical writing score reported on a 0-6 score scale, in half-point increments ( for instance, two readers will judge your GRE analytical essays, awarding each essay a grade ranging from 0-6, with 6 the highest possible score. The powers that be then calculate your analytical writing score by taking the average of your four grades, rounding up the result to the nearest half-point. If one reader awarded your issues essay a 5 and your argument essay a 4, while the other reader gave both your essays 4's, you'd come out with a score of 4.25, rounded up to 4.5)