Why is it cheaper to repay monthly loan at the start of the month [closed]

Assuming I borrow $50000 from the bank where the details are as follow Loan amount : 50000 Annual interest rate : 6% Repayment mode : At then end of the month Loan repayment period : 60 months  Using MS Excel whereby I utilise the PMT method : =PMT(6%/12,60,50000,0,1) I have to make a monthly repayment of$966.64

However if repayment mode is at the start of the month utilising the PMT method : =PMT(6%/12,60,50000,0,1)

I have to make a lower monthly repayment of $961.83 Can any kind soul explain to me why it is cheaper to repay the loan at the start of the month?? closed as off-topic by Bob Jansen♦Jan 27 '16 at 12:32 This question appears to be off-topic. The users who voted to close gave this specific reason: • "Basic financial questions are off-topic as they are assumed to be common knowledge for those studying or working in the field of quantitative finance." – Bob Jansen If this question can be reworded to fit the rules in the help center, please edit the question. • Hi computernerd, welcome to Quant.SE! muffin1974's answer really should be sufficient here. Smaller amount of money outstanding in time period => less interest. – Bob Jansen Jan 27 '16 at 12:34 1 Answer If you make your repayment at the beginning of the month you do not have to pay accrued interest of the amount for the month. So, paying already 961.83$ at the first of each month makes a subtle difference to paying the same amount at the end of the month as you have to pay interest on this open position during those 30 days.

• I dont understand the part "f you make your repayment at the beginning of the month you do not have to pay accrued interest of the amount for the month", could you elaborate on it – Computernerd Jan 27 '16 at 8:14
• @Computernerd This is a query about basic maths and understanding of how interest rates work. It is not really a question about quantitative finance. – jwg Jan 27 '16 at 8:20