# Financial formulas

Question asked by yomango on May 28, 2013
Latest reply on May 29, 2013 by yomango

### Title

Financial formulas

### Post

Saludos. I would like to get some help finding the right formula to do simple interest calculation. There are five fields, one to be calculated from the other 4.  There are4 tables and 5 fielods in each table; fields are Term (t), Monthly Payment (S), % Rate (r) and Principal (P) and a fifth value list field to choose the calculation by Days, Monts or Years (D-MY). If I want to get the Term (t), I type in S, P ,r and the value list field. Same thing for the other tables, If I want to find % Rate(r), I type in the other fields. Of course, if I type in the same information in all the tables I should get the same fields. Calculations could be rounded to 5 or 6 decimals. The calculation does not look to find compound interest, just simple interest; but the formula I=Prt , where I is the final interest amount of the term or S*t should work but it isn't working for me. I ahve used Let(

[I=Payment;
r=Interest_Rate/100;
m=Term];

Case(
Term_in="M";
Round(12* I* (1 - ( 1 + r / 12 ) ^ -m   )/r;9);
Term_in="Y";
Round(12* I* (1 - ( 1 + r / 12 ) ^( -m*12)   )/r;9);
Term_in="D";
Round( 12* I* (1 - ( 1 + r / 12 ) ^( -m/365*12)   )/r;9)
)

)     to get P and is the closest I've come to get it right but not all the time.

I will appreciate the help, just point me out to he right formulas for all 4 financial variables.