The City of Stockholm are working to reduce the emissions from district heating in Stockholm. The aim of this master thesis was to calculate the emission factors for the two district heating grids that AB Fortum Värme operates in Stockholm. The emission factors are calculated on a monthly basis for year 2015. To also get an understanding of how the emission factors will change the coming years calculations have been made based on a scenario for year 2020. A summer week, an autumn week and a winter week was studied with an hour based time resolution. For the three weeks’ emission factors was calculated for the two grids, this was made to get a higher time accuracy. Thereafter the peak load times for the two grids were studied. The result gave that the annual average emission factor for the grid City-södra was 111 gCO2-equivalents/kWh and for the grid Nordvästra the figure was 41 gCO2-equivalents/kWh. Part of the aim of this study was to investigate the effects of reducing peak loads in the district heating grids. The result gave that peak reducing will be most beneficial in the winter. This was because the peaks were most distinct over the winter week. Moreover, the amount of fossil oil will reduce if the peaks in the winter week can be reduced.