# How is the Simple Interest Calculation done in ADDA?

Option 1 - Simple Interest p.a (Considered Billing is Monthly / Quarterly/ Semi-Annually / Annually)

a. Considering the Grace days: Interest Rate is 21% p.a  and Grace Days: 10 days,

If the April Bill Amount as of 1st April is Rs 1000 and the Outstanding is Rs 500, so the Interest will be charged after the grace period that is after the 10th of the April, if any members make the payment within the grace period Interest won't be charged on Rs 1000 but the Interest will be charged on the Outstanding irrespective of the Grace period.

Case1: If the Members Make the Payment on 5th of the April Interest Charge on the April Amount will be Nil but the Interest charge on the Outstanding amount Rs 500 will be from 1st April to 5th April.
Calculation: (21%*500*5) / 365 = Rs 1.43

Case2: If the Members Make the Payment on 16th of the April Interest Charge on the April Amount Rs 1000 will be for 6 days after 10th of April but the Interest charge on the Outstanding amount Rs 500 will be from 1st April to 15th April.
Calculation: (21%*1000*6) / 365 = Rs 3.45
(21%*500*16) / 365 = Rs 4.60
Total Interest Applicable: Rs 8.05

b. Considering Without grace Period Interest will be calculated from the date of the Invoice till the amount is been made in that month. 