The current interest rate which applies to the Postgraduate Loan is 4.6%.
This is based on the rule: Retail Price Index (RPI) plus 3%.
The RPI rate is 1.6% until 31st August 2017. This will change in September based on the RPI from March of that year.
What is the Retail Price Index
The Retail Price Index (RPI), is a measure of UK inflation. It measures changes to the cost of living in the UK. The UK government uses the rate of RPI for many purposes, including setting the interest rate charged on student loans.