# Calculating simple daily interest between two dates

1. ## Calculating simple daily interest between two dates

Hello, I am building a spreadsheet for tracking my travel expenses and disbursements and need a formula in a cell for calculating interest. I can charge 8%/annum on disbursements. So if I paid \$382.50 (E16) for a medical report on Nov 08, 2016 (G3) and the date of my disbursement invoice is today, February 10, 2019 (A16) then, in words, I would need to multiply E16 by the product of the number of days the expense has been outstanding (=G3-A16) and the daily rate of interest 8%/365 or 0.0219. What I have then is =(G3-A16)*0.0219*E16 but I get 7639.60, a number that is wrong. I am not sure if this is relevant but the result I get is not justified to the right like the other numbers in the same column. Can someone guide me?
I am obviously a beginner Excel user but am trying to improve. It took me quite a while just to understand and format dates into numbers, but at least I understand that now.  Register To Reply

2. ## Re: Calculating simple daily interest between two dates

8% / 365 <> 0.02191.
8% / 365 = 0.0002191 because 0.08 / 365 = 0.0002191.
Try like this.  Register To Reply

3. ## Re: Calculating simple daily interest between two dates

That is because your annual intrest of 8% is 0,08 in decimals and daily interest is not 0,0219 (which is 2,19% a day) but 0,000219 a day (or 0,0219%)
you just calculated for an annual rate of 800%  Register To Reply

4. ## Re: Calculating simple daily interest between two dates

to take into account leap years
=SUMPRODUCT(1/(337+DAY(DATE(YEAR(ROW(INDEX(\$A:\$A,B2+1):INDEX(\$A:\$A,C2))),3,))))  Register To Reply

5. ## Re: Calculating simple daily interest between two dates

Thank you, to each of you, for your response. I had the decimal in the wrong place for my daily interest rate! Here I thought my problem had to do with Excel language regarding combining formulas, but it was my simple arithmetic that was wrong. Thank you for your kind guidance. tim201110, taking into account leap years is a great idea, very precise, thank you.  Register To Reply