[en] The ¹²C + p resonance energy of the lowest T = 3/2 state in ¹³N has been determined by using the 100 cm broad-range magnetic spectrograph to measure the incident proton beam energy and a solid state detector to measure the ¹²C(p, p)¹²C yield curve. Phase-shift analyses of 10 proton elastic scattering yield curves taken at a laboratory observation angle of 160degree give a value of the ¹²C + p resonance energy of 14.2325 plus-or-minus 0.0022 MeV. We compare our result with that of a recent time-of-flight measurement (14.230 75 plus-or-minus 0.000 20 MeV) and conclude that the nuclear-reaction energy scale based on the ²¹⁰Po(α) energy is in agreement with the absolute measurement against the meter and second to within an uncertainty of better than 0.016%