Unit Chart


Measure of
API gravity unitless, but referred to in degrees petroleum

<10 API gravity degrees - denser than water

>10 API gravity degrees - less dense than water

cf cubic foot volume 28.31684 liters
1 foot3
ha hectare area 10,000 meters 2
HHV higher heating value energy per unit mass gross calorific value
J Joule energy 1 Newton•meter
LHV lower heating value energy per unit mass net calorific value (subtracts energy used to vaporize water in substance)
m meter length SI base unit
mi mile length 1,609.344 meters
mya million years ago time 1 million years ago
P Poise viscosity 0.1 Pascal•second 5,280 feet
Pa Pascal pressure 1 Newton/meter 2
ppm parts per million volume concentration 10 -6
W Watt power 1 Newton•meter/second
Wh Watt hour energy Watt•hour
t tonne (metric tonne) mass 1,000 kilograms

Metric Prefixes

prefix Value
c centi 10-2
G giga 109
k kilo 103
M mega 106



CCS - Carbon Capture and Sequestration

CO2e - carbon dioxide equivalent

DOE - US Department of Energy

EIA - Energy Information Administration

EOR - Enhanced Oil Recovery

EPA - Environmental Protection Agency

ETS - Emissions Trading System

EU - European Union

GDP - Gross Domestic Product

HRSG - Heat Recovery Steam Generator

IEA - International Energy Agency

IGCC - Integrated Gasification Combined Cycle

IPCC - Intergovernmental Panel on Climate Change

OECD - Organization for Economic Cooperation and Development

R&D - Research & Development

UNEP - United Nation Environment Programme