Measure voltage with PIC18F97J94 (resistor divider)
Optimism can be good but in this instance you need to be more realistic. The ADC input of your PIC may have a theoretical range of 0 to 3V3 but, in practise, this will be more like 50mV to 3.25 volts. Read the data sheet on the ADC and it will tell you what the zero and full-scale errors might be on any particular channel of the device. These errors are equivalent to the digital end-stops of the conversion process and as a rule of thumb I ensure that my biggest and smallest signals are within 50 mV of the specified front-page-of-the-datasheet range.

Other than that your calculation looks accurate enough but why not give a little bit more headroom on the 10V end of the signal? Also, you only need the capacitor to ground to cut-down on noise i.e. C1 is not needed.