Electric Displacement Field Formula

Equation for calculate electric displacement field is,

D = ϵ₀ · E + P

where,
D = Electric displacement field (coulombs/m²)
ϵ₀ = electric constant ( 8.854187817e-12 F m^-1 )
E = Electric field (V/m)
P = Polarization density (coulombs/m²)