NMR can be used as either a qualitative or a quantitative analysis tool. In qualitative mode, peak positions are correct, but the peak areas will not necessarily be accurate relative to one another. In other words, a resonance arising from three protons may not be three times as large as a peak arising from only one proton. Because of the way the experimental parameters must be chosen, quantitative spectra may take signficantly longer to acquire, but the relative areas will be right.

It is relatively easy to achieve quantitative 1H spectra, so most standard experiments are set up to give accurate results for common organic molecules.

If you plan to do ¹³C NMR, on the other hand, you must decide whether you want your spectrum to be qualitative or quantitative.