A fuel quantity measurement system, comprising: one or more pressure sensors configured to operatively connect external to a fuel volume of a fuel tank, operative to sense and output a signal indicative of a pressure inside of the fuel volume and a signal indicative of a pressure external to the fuel volume; one or more hollow pressure tubes configured to be disposed in the fuel volume, the one or more hollow pressure tubes having a first end in fluid communication with the fuel volume and a second end configured to be sealed against an ambient environment external to the fuel tank; one or more temperature sensors configured to operatively connect within the fuel tank, operative to sense and output a signal indicative of a temperature of the fuel tank; and a module including machine readable instructions configured to cause the module to: estimate a quantity of the fuel volume using the signal indicative of the pressure inside of the fuel volume, the signal indicative of the pressure external to the fuel volume, and the signal indicative of the temperature of the fuel tank to calculate a free surface of the fuel volume; and calculate a corrected fuel pressure at the first end of the hollow pressure tube to account for: a height of the one or more pressure sensors relative to a height of the first end of the hollow pressure tube from a bottom of the fuel tank, a compressibility of a fluid held within the hollow pressure tube, and a change in fuel volume in response to a change in temperature of the fuel tank. one or more pressure sensors configured to operatively connect external to a fuel volume of a fuel tank, operative to sense and output a signal indicative of a pressure inside of the fuel volume and a signal indicative of a pressure external to the fuel volume; one or more hollow pressure tubes configured to be disposed in the fuel volume, the one or more hollow pressure tubes having a first end in fluid communication with the fuel volume and a second end configured to be sealed against an ambient environment external to the fuel tank; one or more temperature sensors configured to operatively connect within the fuel tank, operative to sense and output a signal indicative of a temperature of the fuel tank; and a module including machine readable instructions configured to cause the module to: estimate a quantity of the fuel volume using the signal indicative of the pressure inside of the fuel volume, the signal indicative of the pressure external to the fuel volume, and the signal indicative of the temperature of the fuel tank to calculate a free surface of the fuel volume; and calculate a corrected fuel pressure at the first end of the hollow pressure tube to account for: a height of the one or more pressure sensors relative to a height of the first end of the hollow pressure tube from a bottom of the fuel tank, a compressibility of a fluid held within the hollow pressure tube, and a change in fuel volume in response to a change in temperature of the fuel tank. estimate a quantity of the fuel volume using the signal indicative of the pressure inside of the fuel volume, the signal indicative of the pressure external to the fuel volume, and the signal indicative of the temperature of the fuel tank to calculate a free surface of the fuel volume; and calculate a corrected fuel pressure at the first end of the hollow pressure tube to account for: a height of the one or more pressure sensors relative to a height of the first end of the hollow pressure tube from a bottom of the fuel tank, a compressibility of a fluid held within the hollow pressure tube, and a change in fuel volume in response to a change in temperature of the fuel tank.