Unit converter (https://www.iea.org)
Energy Conversion Calculators (http://www.eia.gov)
Conversion Calculator for Units of ENERGY (http://www.cleavebooks.co.uk/)
Energy and Work Converter Calculator (http://www.onlineconversion.com)
Energy and Work Unit Converter (http://www.unit-conversion.info)
GLOBAL SIMULATORS & CALCULATORS
Avoided Emissions Calculator (http://resourceirena.irena.org)
The Solutions Project - how world can reach 100% renewable energy (http://thesolutionsproject.org/)
C-ROADS - The Climate Rapid Overview And Decision-support Simulator (www.climateinteractive.org)
The Global Calculator - a model of the world's energy, land and food systems to 2050 (http://tool.globalcalculator.org)
Climate Change Calculator (http://ig.ft.com)
World energy and carbon counters/widgets (http://oilprice.com/)
ENERGY AND GHG EMISSION MODELS
Tool for Rapid Assessment of City Energy (TRACE): Helping Cities Use Energy Efficiently (http://esmap.org/TRACE)
Energy Policy Simulator (www.energypolicy.solutions)
Long Range Energy Alternatives Planning System (LEAP, http://www.energycommunity.org)
RETScreen Clean Energy Management Software (http://www.retscreen.net/)
EnergyPLAN National Energy Systems Simulation Model (http://www.energyplan.eu/)
HOMER® Microgrid Modelling Software (http://www.homerenergy.com/)
CARBON FOOTPRINT CALCULATORS
Carbon Footprint Calculator (http://www.carbonfootprint.com/)
Carbon Footprint Calculator (http://www.nature.org)
Carbon Footprint Calculator (http://www3.epa.gov)
Carbon Emissions Calculator (http://www.carbonzero.ca)
CoolClimate Calculator (http://coolclimate.berkeley.edu)
Global Footprint Network's Calculator (http://www.footprintnetwork.org)
Environmental Footprint Calculator (http://wwf.org.uk)