Simple (Flat Rate) Interest Calculator: Calculate the Principal (Initial Starting Amount of Money) To Be Lent, Deposited or Borrowed With a Simple (Flat) Interest Rate in Order To Produce a Sum of Money of 285 Units (Dollar, Euro, Pound, etc.) for an Investment Duration Period of 85 Days (2 Months and 23 Days). Annual Simple (Flat) Interest Rate: 2.8%. Transaction Fee: 0.5%
Detailed calculations of the principal
Notations and variables used:
Principal (initial amount), P
Due interest, I = 285
Annual simple interest rate, R = 2.8%
From date: Jul 1, 2016
To date: Sep 24, 2016
Duration, T = 85 days (2 Months and 23 Days)
Transaction fee rate, F% = 0.5%
Transaction fee amount, F
Number of days in a year, N = 365
Calculate P, the principal (the initial amount of money to be lent, deposited or borrowed) to earn the simple (flat rate) interest
The simple (flat rate) interest calculation formula:
I = (P × R × T) ÷ N ⇒
P = (N × I) ÷ (R × T) =
(365 × 285) ÷ (2.8% × 85) =
(100 × 365 × 285) ÷ (2.8 × 85) =
10,402,500 ÷ 238 ≈
43,707.983193277311 ≈
43,707.98
Calculate E, the amount earned after adding the simple (flat rate) interest amount to the principal
E = P + I =
43,707.983193277311 + 285 =
43,992.983193277311 ≈
43,992.98
Calculate L, the amount left after deducting the transaction fee
F = F% × E ⇒
L = E - F =
E - F% × E =
(1 - F%) × E =
(1 - 0.5%) × 43,992.983193277311 =
99.5% × 43,992.983193277311 ≈
43,773.018277310924 ≈
43,773.02
Calculate Pr, the profit of the investment
Pr = L - P =
43,773.018277310924 - 43,707.983193277311 =
65.035084033613 ≈
65.04
Used symbols: % percent, ÷ divide, × multiply, = equal, ≈ approximately equal.
Writing numbers: comma ',' used as thousands separator, point '.' used as a decimal mark.
More operations with the simple (flat rate) interest, calculate the principal:
Calculate principal amount to invest to get a certain simple flat rate interest
Principal = (Number of days in a year × Simple flat rate interest) ÷ (Annual simple flat interest rate × Duration in days)