The air/water partition coefficients of many odorants can be calculated from available data on their vapor pressures and solubilities at 25°. A gas-flow method is described for obtaining equilibrium concentration data to calculate the coefficients of certain odorants for which theoretical or gas chromatographic techniques are not applicable. It is shown that the odor thresholds obtained in airdilution olfactometry agree with those measured by sniff tests on aqueous dilutions, when the air/water partition coefficient is taken into consideration. Similar calculations involving the oil/water partition coefficient show close correspondence between thresholds measured in water or safflower oil dilution. A conversion factor was obtained for comparing squeeze-bottle pair tests with stoppered flask 2/5 tests in the measurement of olfactory threshold.