Volunteering is an essential part of society. It is considered to be a complex phenomenon which is potentially associated with emotional dilemmas. Emotions of volunteers are crucial for their activity. However, their scientific investigation is lacking, especially when it comes to the methodological aspect. This article presents the results of the methodological development of quantitative indicators of the emotional dimension of volunteering. Using the example of an online survey of 274 social, environmental, event, sports, animal welfare and public safety volunteers, the obtained indicators are tested by searching for a connection with the factors of volunteers’ emotions. As part of our methodology, we have developed new emotional indicators of volunteer activity. Based on the results of the study, we proposed such indicators as valence index, emotional burnout, emotional nature and emotional intelligence. The valence index considers two types (two valences) of volunteers’ emotions — positive and negative. Emotional burnout is expressed as a factor analysis model — the causes of burnout. Emotional intelligence is presented as a summary indicator of emotional processes — for instance, exchange, control, etc. The nature of emotions is represented by interval semantic differentials when building a cluster analysis model. By testing the obtained methods, it turns out that formal and informal volunteers have equally high emotional intelligence and are equally susceptible to burnout. The lowest values of the valence index are found among event volunteers, the highest — among public safety volunteers. With age, the chances of burning out decrease with the presence of constant joy and fun, increase due to excessive pity, and decrease due to compassion fatigue. Compared to men, women are more prone to experiencing emotions: both positive and negative, that is, they have a higher valence index and emotional intelligence.