  We present a meta-analysis of star-formation rate (SFR) indicators in the
GAMA survey, producing 12 different SFR metrics and determining the SFR-M*
relation for each. We compare and contrast published methods to extract the SFR
from each indicator, using a well-defined local sample of
morphologically-selected spiral galaxies, which excludes sources which
potentially have large recent changes to their SFR. The different methods are
found to yield SFR-M* relations with inconsistent slopes and normalisations,
suggesting differences between calibration methods. The recovered SFR-M*
relations also have a large range in scatter which, as SFRs of the targets may
be considered constant over the different timescales, suggests differences in
the accuracy by which methods correct for attenuation in individual targets. We
then recalibrate all SFR indicators to provide new, robust and consistent
luminosity-to-SFR calibrations, finding that the most consistent slopes and
normalisations of the SFR-M* relations are obtained when recalibrated using the
radiation transfer method of Popescu et al. These new calibrations can be used
to directly compare SFRs across different observations, epochs and galaxy
populations. We then apply our calibrations to the GAMA II equatorial dataset
and explore the evolution of star-formation in the local Universe. We determine
the evolution of the normalisation to the SFR-M* relation from 0 < z < 0.35 -
finding consistent trends with previous estimates at 0.3 < z < 1.2. We then
provide the definitive z < 0.35 Cosmic Star Formation History, SFR-M* relation
and its evolution over the last 3 billion years.
