Method for calculating a control setpoint of a hybrid powertrain of a motor vehicle, said hybrid powertrain comprising an electric motor that is supplied with current and an internal combustion engine that is equipped with a gearbox and is supplied with fuel, said method comprising: - a step of acquiring a value relating to a power (P r) demanded at the drive wheels of the motor vehicle, and - a step of determining the contribution of the electric motor and of the internal combustion engine in order to satisfy the power demand (P r) at the drive wheels, wherein, at the determination step, a triplet (P th opt, R th opt, P m opt) of three values is calculated, including a value relating to the electromechanical power (P m opt) that the electric motor must supply, a value relating to the thermomechanical power (P th opt) that the internal combustion engine must supply and a value relating to the ratio (R th opt) that must be engaged on the gearbox in order to minimise the sum of the fuel consumption of the internal combustion engine and the current consumption of the electric motor, characterised in that the triplet (P th opt, R th opt, P m opt) is calculated by means of an analytical model of fuel consumption of the internal combustion engine and an analytical model of current consumption (P bat) of the electric motor, and in that the analytical model of fuel consumption of the internal combustion engine as a function of the value relating to the thermomechanical power (P th) that the internal combustion engine must supply is given by the following equation: Q P th = { a 1. P th + Q 0 if P th lies between P th, min and P lim a 2. P th − P lim + Q lim if P th lies between P lim and P th, max with a 1 and a 2 two predetermined constants such that a 1 < a 2, and with Q 0, Q lim, P th,min, P th,max and P lim parameters calculated as a function of the operating point of the internal combustion engine, parameters Q 0, Q lim relating to the fuel consumption limits of the internal combustion engine, at a given speed, parameters P th,min, P th,max relating to power limits that the internal combustion engine can develop, at a given speed, parameter P lim being a power parameter. - a step of acquiring a value relating to a power (P r) demanded at the drive wheels of the motor vehicle, and - a step of determining the contribution of the electric motor and of the internal combustion engine in order to satisfy the power demand (P r) at the drive wheels, wherein, at the determination step, a triplet (P th opt, R th opt, P m opt) of three values is calculated, including a value relating to the electromechanical power (P m opt) that the electric motor must supply, a value relating to the thermomechanical power (P th opt) that the internal combustion engine must supply and a value relating to the ratio (R th opt) that must be engaged on the gearbox in order to minimise the sum of the fuel consumption of the internal combustion engine and the current consumption of the electric motor, characterised in that the triplet (P th opt, R th opt, P m opt) is calculated by means of an analytical model of fuel consumption of the internal combustion engine and an analytical model of current consumption (P bat) of the electric motor, and in that the analytical model of fuel consumption of the internal combustion engine as a function of the value relating to the thermomechanical power (P th) that the internal combustion engine must supply is given by the following equation: Q P th = { a 1. P th + Q 0 if P th lies between P th, min and P lim a 2. P th − P lim + Q lim if P th lies between P lim and P th, max with a 1 and a 2 two predetermined constants such that a 1 < a 2, and with Q 0, Q lim, P th,min, P th,max and P lim parameters calculated as a function of the operating point of the internal combustion engine, parameters Q 0, Q lim relating to the fuel consumption limits of the internal combustion engine, at a given speed, parameters P th,min, P th,max relating to power limits that the internal combustion engine can develop, at a given speed, parameter P lim being a power parameter.