8400 yuan. The loan interest rate is 5.6% and the loan amount is 50,000 yuan. The interest for three years is calculated as follows: interest is equal to the principal times the interest rate times the time. The interest for three years is equal to 50,000 yuan multiplied by 5.6% and 3 years is equal to 8,400 yuan. This is based on a simple interest calculation. In fact, when calculating interest, banks use the compound interest calculation method, that is, the annual interest will become the principal of the next year, which leads to the final interest being higher than the simple interest.