Data shows that the total tuition fee and maintenance loan balance is up 12% on the previous year's figures.
Graduates start repaying their debt once their income reaches £21,000 but after 30 years outstanding debt is written off.
For those repaying loans in 2017 the average sum owed at the start of repayment was £19,280.
That compares with £32,220 for English students, £20,990 for Northern Irish students and £11,740 for Scottish students who do not pay fees if they study in Scotland.
The figures come from the Student Loans Company and cover 2016/17.
Welsh domiciled students have been able to claim a grant towards their tuition fees since 2012-13 - a sum of £4,954 in 2017-18.
But the grants are due to be scrapped from 2018-19 with help for maintenance costs introduced instead, under plans unveiled last year.
At the end of 2016-17 there were 304,900 borrowers of higher education student loans in Wales, with 191,100 liable for repayment.
As of the end of April 2017 there are 41,430 borrowers who had fully repaid, amounting to 16.4% of the overall total.
The data covers Welsh domiciled students studying in higher education in the UK and EU students studying in Wales.
The overall student loan debt for Welsh students has reached £3.7bn, new figures show.