Coastal blue carbon ecosystems services are the backbone of millions of coastal inhabitants, for their livelihoods and food security. Yet, rapid degradation of mangroves, caused by aquaculture, urban development, over fishing and climate change, has resulted in loss of carbon stocks and high GHG emissions. During the last decade, scientific understanding of carbon sequestration and potential emissions from mangroves ecosystems has influenced to develop policy, recommendations and methodologies for better quantification of avoided emissions from development projects. The EX-Ante Carbon-balance Tool (EX-ACT), developed by Food and Agriculture Organization of the United Nations (FAO), provides a snapshot of carbon-balance impacts from adoption of alternative land management options as compared to a ‘business as usual’ scenario. EX-ACT fully incorporates guidelines and datasets of the IPCC 2006 and 2013 (wetlands supplement). EX-ACT helps project designers to estimate and prioritize project activities with high benefits in economic and climate change mitigation terms. EX-ACT is suitable in analysing coastal blue carbon projects, programmes and policy formulation as already being applied on case-studies on mangrove restoration, agriculture