A fuel delivery system for use, for example in a gas turbine engine system, includes a fuel metering unit including a main fuel inlet. The fuel metering unit includes fuel pressure and temperature sensors. A cavitating venturi is in fluid communication with the main fuel inlet and includes venturi characteristics such as throat diameter. A fuel nozzle is in fluid communication with the venturi for delivering fuel to the gas turbine engine. A controller is connected to the pressure temperature sensors and is operable to calculate a flow rate of fuel through the nozzle based upon the signals from the pressure and temperature sensors and the fuel and venturi characteristics. A variable cavitating venturi may be arranged within the throat to vary the area and adjust the flow rate through the venturi. The cavitating venturi can also be used at the fuel nozzle to further simplify the fuel delivery system.