Calibration curves and dilution factors

I am currently taking a course where we are exploring nitrate concentrations in water samples. We are using a UV-Vis Spectrophotometer and have created a calibration curve in the first part of the experiment. 


Now in the second part of the experiment we need to measure the absorbance rates and use the calibration curve produced in the first part of the experiment to find the nitrate concentrations. 


I expect that I need to multiply the concentration obtained from my calibration curve by the dilution factor used during the determination of the absorption rate, however, I would like to get this confirmed and understand better how this works. 


