A light-emitting device includes: light-emitting elements whose luminous energy is controlled according to a current value and a pulse width of a driving signal; a storage unit that stores first and second coefficients for every light-emitting element; a pulse width determining unit that determines the pulse width of the driving signal supplied to each light-emitting element on the basis of the first coefficient, a current value determining unit that determines a current value of the driving signal supplied to each light-emitting element on the basis of the second coefficient, a driving unit that supplies the driving signal having the current value determined by the current value determining unit within the determined pulse width determined, to the light-emitting element, and a coefficient determining unit that calculates the first coefficient based on target values of a light amount and first peak light amounts of one of the light-emitting elements, and calculates the second coefficient.