Pick your light, set it the way you set it in the maker's app, and type how high it hangs above the water and how deep the coral sits. What comes back is a range for the spot right under the light, worked from other hobbyists' readings of the same light, with the reasons it is a range written beside it.
The estimate itself needs JavaScript, because it is worked from the height and depth you type.
This is an estimate built from a few hobbyists' readings, not a measurement. The range is wide on purpose, because those readings disagree, for some lights by nearly two times, and one owner's corals burned at a step the low end called small. It is for the spot right under the light; anywhere off to the side reads lower. A PAR meter reading beats it every time.
Radion XR15 G6 Blue. Where its PAR range comes from: Low: a single XR15 G6 Blue over a 24 x 20 in tank, read 3 to 15 in deep (ParWise, corrected up 17%). High: Apogee readings under three XR15 G6 Blues at 80% on a 48 x 28 in tank. Mount heights were not given, which is most of the gap.
AI Blade Coral Glow 12". Where its PAR range comes from: Two owners' readings of Blade Coral Grows 1 to 2 in above the water (a 12 in on a 15 in cube; a 21 in over a 16 in deep tank, VBR meter), taken at 70 to 100% for the Glow, which AquaIllumination rates below the Grow for PAR.
Kessil A360X. No PAR estimate for the Kessil A360X. The published readings found so far are too few to set a low and a high: one owner's pair of A360Xs, with the violet channel on, is not enough to say what one light gives at a known setting.