In Poland, the largest consumer of hard coal is the energy sector. In the years 2007–2013 its share of the total domestic consumption amounted to 53–56% (40,4–47,5 million tons). Because of the high demand from the transport sector, the most frequently hard coal is transported by rail. The article focuses on assessing the cost of coal supply to power plants. For the selected price levels hard coal consumed by the power plant (from 8.0 to 12.5 zł/GJ) was estimated share of the costs of its deliveries for several levels of transport distances (from 20 to 400 km). Transport rates taken from PKP Cargo tariffs in force in 2014. Prices of coal and the transport costs are calculated for two exemplary calorific value: 21 and 23 MJ/kg (approx. 5,000 and 5,500 kcal/kg). The results of calculation are presented in two-dimensional tables. For example, when the price of hard coal consumed by the power plant is 11 zł/GJ, and the use of 60% discount of the transport, the share of coal transport a calorific value of 21 MJ/kg (approx. 5,000 kcal/kg) varies from 7 to 20% and the calorific value 23 MJ/kg (approx. 5,500 kcal/kg) – from 7 to 18%.