The electric field a distance r away from a point charge Q is given by:

E = kQ / r²

where points from the charge to the point where the field is being calculated.

The electric field from a positive charge points away from the charge; the electric field from a negative charge points toward the charge.

The field-line pattern reinforces the 1/r² dependence of the field, as the lines get further apart as you get further away from the charge.