Hello, when calculating the interest during the construction period, we must first determine the loan time. The algorithm of borrowing at the beginning of the year is different from that of borrowing in the middle of the year. Generally speaking, when making investment estimates, it is assumed to borrow money in the middle of the year.

Loan interest in the first year of construction = 1/2* loan amount in the current year * interest rate.

N+ 1 year loan interest during the construction period = total loan at the beginning of the year * interest rate+1/2* current loan amount * interest rate.

Example: The loan amount of a project is1000000 yuan, which will be invested in three years.

Loan interest in the first year of construction = 1/2* 100*0.06=3.

Loan interest for the second year of construction = (100+3) * 0.06+1/2 * 300 * 0.06 =15.18.

Loan interest in the third year of construction = (100+3+300+15.18) * 0.06+1/2 *100 * 0.06 = 28.09.

Loan interest during construction period = 3+15.18+28.09 = 46.27.