I think this is what your looking for. I think you have to calibrate it yourself for each specific airplane/tank. I dont think the numbers will translate to another airplane. To calibrate is easy. After emptying the tank(s) you refill the tank(s) in increments and take readings on the fuel dipstick as you fill.
http://www.aircraftspruce.com/catalog/pspages/fuelhawkuniv16.php?clickkey=1377262