More than a third of university students live on less than £40 a week, a survey shows.
Meanwhile, one in 10 survive on an average of just £9.50, after rent is paid, the Times Higher Education Supplement found.
However, a wealthier 11% had £150 to spend. Some 20% of overseas students had this level of income.
The THES interviewed more than 2,000 students at 30 universities across the UK for the survey.
Part-time jobs
It also found that 39% expected to graduate with debts of more than £10,000.
Two-fifths said they worked part-time to boost their income.
Meanwhile, a quarter were living at home, as it was a cheaper option.
The findings come as the government attempts to push plans for annual tuition fees in England of up to £3,000 through parliament.
The National Union of Students says this will mean some graduates starting work with debts of up to £30,000.
However, ministers say the figure will be lower.
The survey discovered that academic success was still students' main worry, with 29% citing this as their biggest concern.
Next, on 14% each, were finding a job after graduation and the level of debt on leaving university.
Day-to-day financial worries were the biggest concern for 9% of undergraduates.