More than 80 per cent of charities in the north of England would fold without the contributions of volunteers, according to a report by the think tank IPPR North.
The report, The Value of Volunteering in the North, says there were found to be about 930,000 volunteers in the north of England, contributing 67 million hours to charities in the region each year.
If all the volunteers were paid a salary for the hours they worked, the report says, this would cost between £480m, if paid the minimum wage, and £810m, if paid at 80 per cent of the regional average.
The report, which is based on a longitudinal study of charities in north-west and north-east England, and Yorkshire and the Humber, says 81 per cent of charities in the region agreed they could not continue without their volunteers.
Fifty-seven per cent of respondents "strongly agreed" that they could not keep going without their volunteers; 24 per cent "agreed" with the statement.
Three in four small charities felt they were heavily dependent on volunteers, says the report, and 77 per cent of all volunteering in the region took place in small charities.
This meant that 22 million hours a year were donated to northern charities with annual incomes of less than £10,000, according to the report.
Charities in north-west England were the most reliant on volunteers, with 32 million hours worked, which would cost £230m they were paid the minimum wage.
Yorkshire and the Humber charities benefited from 25 million hours worked by volunteers, and those in north-east England relied on 11 million volunteer hours.
Volunteer-dependent charities were prevalent in both poor and rich areas of the north, the report says.
The report adds that the findings show the important role volunteers play in the northern charity sector, but government should be "realistic" about the extent to which this volunteering capacity could be increased.
This is because volunteering rates have remained consistent over the past 20 years despite numerous government interventions to boost it, the report says.
Jack Hunter, research fellow at IPPR North and co-author of the report, said: "Many of the smallest organisations are often completely reliant on the contribution of unpaid volunteers who give their time willingly and on a regular basis.
"Without them, a vast swathe of civil society organisations would simply cease to exist, with huge consequences for places up and down the north, and for the state of the Northern Powerhouse economy."