The Corporate Citizenship Company, a consultancy that promotes corporate social responsibility, and the Vodafone UK Foundation are to publish a report that will help charities quantify their social returns on investment. They have been working with a reference group of charities that includes NCH, Shelter, 4Children and Tomorrow's People.
Tomorrow's People has estimated that for every £100 of funding investment it receives, it benefits society by £160.
So far, the methodology in the project has been applied only to initiatives that help people gain employment, but researchers believe it could have far wider application.
Sarah Shillito, head of the Vodafone UK Foundation, said it could help charities such as the Samaritans calculate the "ripple effect" of suicide on society.
But she said charities should be cautious about claiming sole responsibility for outcomes. "You can't say nothing else has made a difference," she said.
She added that even if charities did not want to place a monetary value on their work, they could still use the tool to help assess the social impact of their activities.