How to make a diptube to measure your cylindrical tank, kettle, or fermenter.
Units of measure are Inches (yielding Gallons US) or Centimeters (yielding Liters).
I haven't found a better calculator, so you'll have to create a dipstick and mark it off at Inch or Centimeter increments and then use this tool to figure out the volume measurement at each mark by changing the height.