That’s why we developed this petroleum calculator to allow you to focus more of your day on making money and less of it doing math. This calculator is a simple and useful tool for calculation on petroleum products to obtain the following: Gross Standard Volume Metric Tons (in vac) Metric Tons (in air) Gross Barrels US Barrels @ 60°F US Gallons Short Tons Long Tons V.C.F - Volume Correction Factor W.C.F - Weight Correction Factor