Tank volume, from the dipstick reading

Helpful info

What is a dip chart?

A dip chart, also called a dip table or a dipstick table, lists the volume a tank holds at each dipstick reading, from 0 up to full. Print one, tape it inside the lid, and a reading becomes a volume in a single glance.

Dipping a tank is how one determines how much contents are in a tank. Unless the tank is perfectly rectangular, the reading from the measuring device and the contents of the tank are not a linear relationship. In other words, the change in volume per unit measurement is different for every value. A dip chart is necessary to determine the contents and/or empty space. This site contains calculators to get volume from dip readings and generate dip charts for specified tank geometries.

How to dip a tank

You need four numbers: the inside diameter (or width and height), the inside length, and a dipstick reading. Keep all measurements in inches and the calculators do the rest.

The following steps will help you gain a fairly accurate measurement.

1. With a large wrench, open the fill cap on the top of the tank.
2. Using a graduated rod or a metal tape measure, slowly extend the measuring tool down into the fuel until you hit bottom. Make sure you go straight down; angled measurements will lead to skewed or inaccurate results.
3. Slowly bring the measurement device out of the tank, until you see or feel the point where it contacted the liquid.
4. Remember the measurement or have an assistant write it down.
5. With a rag or a paper towel, dry the wet portion of the measurement device.
6. Secure the fill cap back on the tank. It is important to tighten it securely.
7. Using a calculator or a dip chart, look up the measurement to know the volume of contents in the tank.

These instructions, along with everything else on this site, are as is and for informational purposes only. Please consult the manufacturer's literature for specifics.