We present the calibration between the dust continuum luminosity and interstellar gas content obtained from the Valparaiso ALMA Line Emission Survey (VALES) sample of 67 main-sequence star-forming galaxies at 0.02 <z <0.35. We use CO(1-0) observations from the Atacama Large Millimetre/submillimetre Array to trace the molecular gas mass, M-H2, and estimate the rest-frame monochromatic luminosity at 850 mu m, L-nu 850, by extrapolating the dust continuum from MAGPHYS modelling of the far-ultraviolet to submillimetre spectral energy distribution sampled by the Galaxy And Mass Assembly survey. Adopting alpha(CO) = 6.5 (K km s(-1) pc(2))(-1), the average ratio of L-nu 850/M-H2 = (6.4 +/- 1.4) x 10(19) erg s(-1) Hz(-1) M-circle dot(-1), in excellent agreement with literature values. We obtain a linear fit of log(10) (M-H2/M-circle dot) = (0.92 +/- 0.02) log(10)(L-nu 850/erg s(-1) Hz(-1)) - (17.31 +/- 0.59). We provide relations between L-nu 850, M-H2 and M-ISM when combining the VALES and literature samples, and adopting a Galactic alpha(CO) value.