An apparatus for controlling an internal combustion engine having a plurality of cylinders and fuel injectors provided to inject fuel in a sequential fashion for the respective cylinders. Fuel injection is made twice from a given fuel injector. The control circuit calculates a first value for the amount of fuel injected from the fuel injector during the first fuel injection and a second value for the amount of fuel injected from the fuel injector during the second fuel injection. During transition of the engine operation, an engine load variation is produced between the times at which the first and second values are calculated. A correction factor is calculated based on the engine load variation with an estimation of a first value to be calculated for the cylinder when the fuel injected during the first and second fuel injections is charged in the cylinder.