What is Reverse Interest and Why Should You Care?
Reverse Interest helps you figure out the original investment or loan amount when you know the accumulated total. Given the final amount, interest rate, and number of periods, it calculates how much you started with.
How to Calculate Reverse Interest
Here is the formula:
[\text{Principal} = \frac{\text{Accumulated Amount}}{(1 + r)^{n}}]
Where:
- Principal is the original amount of money.
- Accumulated Amount is the final amount after interest.
- r is the interest rate per period as a decimal.
- n is the number of compounding periods.
Calculation Example
Suppose your investment has grown to $500,000 over 4 years at 6% annual interest.
First, convert the rate: 6% = 0.06.
[\text{Principal} = \frac{500{,}000}{(1 + 0.06)^{4}}]
Calculate the denominator:
[(1.06)^{4} \approx 1.2625]
Divide:
[\text{Principal} = \frac{500{,}000}{1.2625} \approx 396{,}039.03]
Your initial investment was approximately $396,039.03.
| Parameter | Value |
|---|---|
| Accumulated Amount | $500,000 |
| Interest Rate | 6% per year |
| Number of Periods | 4 years |
| Principal Amount | $396,039.03 |