What are the dimensions of the 3 sizes of coals that you stock? December 09, 2019 13:46 Updated Follow All the coals come in bags of 10. There are three sizes of coals: Small Coals: 40mm x 40mm x 40mm Medium Coals: 50mm x 50mm x 50mm Large Coals: 60mm x 60mm x 60mm Related articles How to choose a chimney cowl Gas Cabinet Heater Buying Guide/FAQs Cabinet Gas Heaters Comparison Can I fit a Provence Heater in a fireplace? What's the Minimum Room Requirement for the Calor Mini Super Heat? Comments 0 comments Please sign in to leave a comment.