A billing charge calculation method for use in a sheet manufacturing apparatus that manufactures a sheet using a material including a fiber, includes: acquiring a quantity of output of the manufactured sheets; and calculating a billing charge according to the quantity of the output of the sheets, in which, in the calculating of the billing charge, a charge that includes a quantity-based charge which is obtained by multiplying the quantity of the output of the sheets by a charge per unit quantity is calculated as the billing charge.