I have a loan that was originally $100,000. It is worth $116,971.41 today. It has been accruing 6% annual interest, compounded daily. I do not know the start date.
How do I calculate what the value of this loan was 90 days ago?
Interest would be calculated as
A= P * (1+r/n)^nt
where A=ending amount, P=principal, r=rate, n=number of times compounded per T, t=time rate is over (usually year).
So solving for P where A=116971.41, r=.06, n=365, t=90/365 (so nt=90) would give you
P = A/(1+r/n)^nt
You should end up with a number just over $115,250.