How to convert illuminance in lux (lx) to luminous intensity in candela (cd).
You can calculate candela from lux and distance from light source.
You can't convert lux to candela, since candela and lux do not represent the same quantity.
The luminous intensity Iv in candela (cd) is equal to 0.09290304 times the illuminance Ev in lux (lx),
times the square distance from the light source d2 in square feet (ft2):
Iv(cd) = 0.09290304 × Ev(lx) × (d(ft))2
So
candela = 0.09290304 × lux × square feet
Or
cd = 0.09290304 × lx × ft2
The luminous intensity Iv in candela (cd) is equal to the illuminance Ev in lux (lx),
times the square distance from the light source d2 in square meters (m2):
Iv(cd) = Ev(lx) × (d(m))2
So
candela = lux × square meters
Or
cd = lx × m2