Simple flat rate interest calculator: calculate the due interest on an amount of money lent, deposited or borrowed by the interest rate, principal (starting amount), duration and additional transactional fees (withdrawal, payment in advance)

Calculate simple flat rate interest on a principal borrowed, lent

Simple flat rate interest = (Principal × Annual simple flat interest rate × Duration in days) ÷ Number of days in a year

Latest calculated simple flat rate interest values

Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 600 units (Dollar, Euro, Pound, etc.), from date: Nov 23, 2021, to date: Dec 11, 2021, namely for a period of 18 days, with an annual simple flat interest rate of 20% if the commission fee (withdrawal) is 0%. Dec 07 18:17 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 600 units (Dollar, Euro, Pound, etc.), from date: Nov 23, 2020, to date: Dec 11, 2021, namely for a period of 383 days (13 Months without 12 Days), with an annual simple flat interest rate of 20% if the commission fee (withdrawal) is 0%. Dec 07 18:16 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 0 units (Dollar, Euro, Pound, etc.), from date: Feb 21, 2019, to date: Jan 21, 2021, namely for a period of 700 days (23 Months), with an annual simple flat interest rate of 8.24% if the commission fee (withdrawal) is 0%. Dec 07 18:16 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of - 1,650 units (Dollar, Euro, Pound, etc.), from date: Apr 08, 0828, to date: Jul 21, 1998, namely for a period of 427,437 days (14,043 Months and 13 Days), with an annual simple flat interest rate of 0.01% if the commission fee (withdrawal) is 0%. Dec 07 18:16 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 100 units (Dollar, Euro, Pound, etc.), from date: May 26, 2017, to date: Jun 26, 2017, namely for a period of 31 days, with an annual simple flat interest rate of 3% if the commission fee (withdrawal) is 0%. Dec 07 18:14 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 0 units (Dollar, Euro, Pound, etc.), from date: Feb 22, 0988, to date: Feb 22, 2017, namely for a period of 375,835 days (12,348 Months), with an annual simple flat interest rate of 0% if the commission fee (withdrawal) is 0%. Dec 07 18:12 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 1 units (Dollar, Euro, Pound, etc.), from date: Jun 24, 0764, to date: Jul 24, 2018, namely for a period of 458,044 days (15,049 Months), with an annual simple flat interest rate of 2% if the commission fee (withdrawal) is 868%. Dec 07 18:12 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 1 units (Dollar, Euro, Pound, etc.), from date: May 25, 0114, to date: Jun 25, 2018, namely for a period of 695,453 days (22,849 Months), with an annual simple flat interest rate of 130% if the commission fee (withdrawal) is 0%. Dec 07 18:11 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 0 units (Dollar, Euro, Pound, etc.), from date: May 25, 0290, to date: Jun 07, 2017, namely for a period of 630,787 days (20,725 Months without 18 Days), with an annual simple flat interest rate of 0% if the commission fee (withdrawal) is 0%. Dec 07 18:11 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 0 units (Dollar, Euro, Pound, etc.), from date: May 18, 0552, to date: Sep 13, 2017, namely for a period of 535,198 days (17,584 Months without 5 Days), with an annual simple flat interest rate of 0% if the commission fee (withdrawal) is 180%. Dec 07 18:10 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 0 units (Dollar, Euro, Pound, etc.), from date: May 29, 0608, to date: Jun 24, 0804, namely for a period of 71,614 days (2,353 Months without 5 Days), with an annual simple flat interest rate of - 3% if the commission fee (withdrawal) is 0%. Dec 07 18:10 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 65,000 units (Dollar, Euro, Pound, etc.), from date: Jul 06, 2017, to date: Jul 06, 2020, namely for a period of 1,096 days (36 Months), with an annual simple flat interest rate of 7% if the commission fee (withdrawal) is 0%. Dec 07 18:10 UTC (GMT)
Calculate due interest earned by a principal (initial amount of money lent, deposited or borrowed) of 100 units (Dollar, Euro, Pound, etc.), from date: Jun 11, 0958, to date: Jul 11, 2018, namely for a period of 387,187 days (12,721 Months), with an annual simple flat interest rate of 1.5% if the commission fee (withdrawal) is 0%. Dec 07 18:09 UTC (GMT)
All users calculated simple flat rate interest values


Simple flat rate interest.

Interest

  • When someone lends money to someone else, the borrower usually pays a fee to the lender. So the due interest is a sum paid or charged for the use of money or for borrowing money. The interest depends on: 1) the period of the loan 2) the amount of money lent or borrowed (called principal) and 3) the interest rate (the percentage of the principal charged as interest).
  • For example, for some bank deposits is not uncommon to pay an interest rate of 3.5% on the principal, annualy. Banks are also using these temporarily owned amounts of money by introducing them back into the cash flow circuit or are granting loans (for investments, for example) on which they are again charging interest.

Annual simple flat interest rate

  • The simple annual interest rate, or the percentage of the principal charged as interest for a period of one year, shows us that for an amount of 100 units (ex: Dollar, Euro, Yen, Pound, Franc), in a year, the interest is calculated as a percentage p% of the principal: I = p% × 100 units.
  • A deposit of S units generates a one year simple interest of: I = S × p% units, and in n years, the same deposit of S units generates an interest of: I = S × p% × n units.

Annual simple flat rate interest formula:

  • I = S × p% × n

  • I = n years simple flat rate interest charged
  • S = initial amount (principal)
  • p% = annual simple flat interest rate (percentage of the principal charged as interest)
  • n = number of years of the lending or borrowing the money

Examples of how the simple flat rate interest formula works:

  • 1) What interest, I, generates in n = 5 years a principal of S = 20,000 units if the annual simple flat interest rate is p% = 3.5%?
    Answer:
    I = S × p% × n = 20,000 × 3.5% × 5 = 20,000 × 3.5 ÷ 100 × 5 = 1,000 × 3.5 = 3,500 units
  • 2) What is the simple flat interest rate, p%, if a principal of S = 12,000 units is charged a n = 6 years interest of I = 2,880 units?
    Answer:
    I = S × p% × n =>
    p% = I ÷ (S × n) = 2,880 ÷ (12,000 × 6) = 0.04 = 4%.

Annual simple flat rate interest formula calculated for a period of n years:

  • Interest, I = S × p% × n
  • Principal, S = I ÷ (p% × n)
  • Interest rate, p% = I ÷ (S × n)
  • Number of years (period): n = I ÷ (S × p%)

Annual simple flat rate interest formula calculated for a period of m months:

  • Interest, I = (S × p% × m) ÷ 12
  • Principal, S = (12 × I) ÷ (p% × m)
  • Interest rate, p% = (12 × I) ÷ (S × m)
  • Number of months of the period, m = (12 × I) ÷ (S × p%)

Annual simple flat rate interest formula calculated for a period of d days:

  • Interest, I = (S × p% × d) ÷ 365
  • Principal, S = (365 × I) ÷ (p% × d)
  • Simple flat interest rate, p% = (365 × I) ÷ (S × d)
  • Number of days of the period, d = (365 × I) ÷ (S × p%)

More examples of how the simple flat rate interest formula works:

  • 1) Calculate the due interest on a principal of S = 400 units in m = 5 months, with a simple flat interest rate of p% = 4%.
    Answer:
    I = (S × p% × m) ÷ 12 = (400 × 4% × 5) ÷ 12 = (400 × 4 ÷ 100 × 5) ÷ 12 = 16 × 5 ÷ 12 = 20 ÷ 3 = 6.67 units
  • 2) Calculate the due interest generated by a principal of S = 400 units in m = 5 months if the simple flat interest rate of p% = 4.5%.
    Answer:
    I = (S × p% × m) ÷ 12 = (400 × 4.5% × 5) ÷ 12 = (400 × 4.5 ÷ 100 × 5) ÷ 12 = 18 × 5 ÷ 12 = 15 ÷ 2 = 7.5 units.