In this guide, we explore how proving the value of volunteers can significantly improve your nonprofit’s volunteer retention, enhance supporter experiences, and strengthen funding applications. By implementing simple but effective strategies to highlight volunteer contributions, your organisation can reap tangible benefits for all stakeholders. Volunteers are essential to the mission of most nonprofits. However, treating volunteer contributions as “free labour” is a double-edged sword for fundraising managers. The economic value of volunteers is substantial, with the UK Government’s Office for National Statistics estimating volunteer work contributes between £23 billion and £50 billion annually to the economy. Yet, quantifying the value of volunteer contributions remains a challenge many nonprofit leaders shy away from. This guide emphasises why calculating volunteer value is essential and provides actionable steps to help nonprofits appreciate and measure their volunteers’ impact.