Calculating Unpaid Balance

Oct 13, 2025 by wbrum.org 62 views

Understanding the Problem

Calculating the unpaid balance on a loan after a certain period is crucial for individuals and businesses to understand their financial obligations. In this article, we will explore the expressions that can be used to determine the unpaid balance after 5 years on an $80,000 loan with an APR of 4.8%, compounded monthly, if the monthly payment is $519.17.

Loan Details

Principal Amount: $80,000
Annual Percentage Rate (APR): 4.8%
Compounding Frequency: Monthly
Monthly Payment: $519.17
Loan Term: 5 years

Calculating Unpaid Balance

To calculate the unpaid balance after 5 years, we need to use the formula for calculating the future value of an annuity. The formula is:

FV = PMT x (((1 + r)^n - 1) / r)

Where:

FV = Future Value (unpaid balance)
PMT = Monthly Payment
r = Monthly interest rate (APR / 12)
n = Number of payments (loan term * 12)

Expression A: Using the Formula

The first expression to calculate the unpaid balance is:

$80,000(1+0.048)^5 + \frac{519.17}{0.048/12} \times ((1 + 0.048/12)^{60} - 1) - \frac{519.17}{0.048/12} \times ((1 + 0.048/12)^{60} - (1 + 0.048/12)^{5})$

This expression uses the formula for calculating the future value of an annuity, taking into account the principal amount, monthly payment, and interest rate.

Expression B: Using the Formula with Simplification

The second expression to calculate the unpaid balance is:

$80,000(1+0.048)^5 + \frac{519.17}{0.048/12} \times ((1 + 0.048/12)^{60} - 1) - \frac{519.17}{0.048/12} \times ((1 + 0.048/12)^{55} - 1)$

This expression simplifies the calculation by removing the unnecessary term in the second part of the formula.

Expression C: Using the Formula with Further Simplification

The third expression to calculate the unpaid balance is:

$80,000(1+0.048)^5 + \frac{519.17}{0.048/12} \times ((1 + 0.048/12)^{60} - 1)$

This expression further simplifies the calculation by removing the unnecessary term in the second part of the formula.

Comparison of Expressions

All three expressions calculate the unpaid balance after 5 years on the loan. However, Expression C is the most simplified and easiest to calculate.

Conclusion

Calculating the unpaid balance on a loan after a certain period is crucial for individuals and businesses to understand their financial obligations. In this article, we explored the expressions that can be used to determine the unpaid balance after 5 years on an $80,000 loan with an APR of 4.8%, compounded monthly, if the monthly payment is $519.17. We compared three expressions and found that Expression C is the most simplified and easiest to calculate.

Recommendation

When calculating the unpaid balance on a loan, it is essential to use the correct formula and simplify the calculation as much as possible. By using Expression C, individuals and businesses can easily determine the unpaid balance after 5 years on the loan.

Future Value of an Annuity Formula

The formula for calculating the future value of an annuity is:

FV = PMT x (((1 + r)^n - 1) / r)

Where:

FV = Future Value (unpaid balance)
PMT = Monthly Payment
r = Monthly interest rate (APR / 12)
n = Number of payments (loan term * 12)

Monthly Interest Rate Formula

The formula for calculating the monthly interest rate is:

r = APR / 12

Where:

r = Monthly interest rate
APR = Annual Percentage Rate

Number of Payments Formula

The formula for calculating the number of payments is:

n = loan term * 12

Where:

n = Number of payments
loan term = Loan term in years

Calculating Unpaid Balance with Different Loan Terms

To calculate the unpaid balance with different loan terms, we can use the same formula and expressions as before. We just need to change the loan term and recalculate the number of payments.

Calculating Unpaid Balance with Different APRs

To calculate the unpaid balance with different APRs, we can use the same formula and expressions as before. We just need to change the APR and recalculate the monthly interest rate.

Calculating Unpaid Balance with Different Monthly Payments

To calculate the unpaid balance with different monthly payments, we can use the same formula and expressions as before. We just need to change the monthly payment and recalculate the future value.