Home » Interest Rate Calculators » Installment Loan Calculators
Compound Interest Calculator
Compound interest calculator for the growth of a one-off investment with compound interest of variable compounding frequency.
Present Value Calculator
Interest rate calculator for the present value of future income, that is, what future income is worth as of today.
Inflation Calculator
Interest rate calculator determining the loss of real purchasing power of money balances from inflation over variable time spans.
Return on Investment Calculator
Interest rate calculator for the rate of return on an investment (ROI) taking the invested amount and sales proceeds as inputs.
Savings Plan Calculator
Interest rate calculator that determines the growth of a savings plan with regular deposits and interest earnings.
Pension Present Value Calculator
Financial calculator that determines the present value of a pension or other types of long-term regular income.
Asset Valuation
Financial calculator for asset valuation based on regular income such as dividends for stocks or rents for real property.
Outstanding Loan Amount Calculator for Installment Loans
Calculates the outstanding loan amount of an installment loan from the height of installments and underlying interest rate.
Height of Installment Calculator for Installment Loans
Height of installment calculator for installment loan contracts calculates installments from the paid out loan and underlying interest rate.
Underlying Interest Rate Calculator for Installment Loans
Calculates the underlying interest rate of an installment loan from the start and end of term loan balances.

Installment Loan Calculators

Installment loans are a very common form of consumer credit with repayments in equal installments at regular intervals. Mortgages, car loans, cash advances, and installment purchases are examples of this type of contract. We provide installment loan calculators to calculate the terms of such loans.

Five parameters define the contractual terms of installment loans: the initial loan balance, the remaining loan balance at the end of the term, the contract term, the installment amount and the loan interest rate. However, the choice of these parameters is not arbitrary, because the remaining fifth can be calculated from combinations of four.

There are therefore five variants of installment loan calculators, of which we select three with the following results: the outstanding loan amount at the end of the term, the amount of the installment payments and the loan interest rate.

Outstanding Loan Amount Calculator for Installment Loans

The end of term outstanding loan amount calculator takes the initial loan balance, term, installments, and loan rate for input. From this, it computes the outstanding loan balance at the end of the contract.

Variant of installment loan calculators for remaining loan balance.
End of term outstanding loan balance depending on the height of installments.

The above diagram shows the end of term loan balance depending on the installment payments. The part of the loan that has been repaid at the end of the contract is obviously proportional to the amount of the installment.

Height of Installment Calculator for Installment Loans

The height of installment calculator takes the initial loan balance, term, end of term loan balance, and loan rate for input. From this, it computes the height of regularly payable installments.

Amortization dynamics for an installment loan.
Interest and amortization portions of installments repaying a loan within a 10 year term.

Generally, consumers are better off with installment loan contracts that repay quickly. This is because longer running contracts charge more interest, which ultimately raises costs. The diagram above visualizes this relationship, since interest is highest and amortization lowest the longer the contract is still running.

Underlying Interest Rate Calculator for Installment Loans

The underlying interest rate calculator determines the interest rate that a lender charges. Calculation inputs are the initial loan balance, the ending loan balance, the height of installments, and the term of the contract.

Graph showing the underlying interest rate for different heights of installments.
Underlying interest rates depending on height of monthly installments.

As the diagram above demonstrates, an underlying interest rate can be determined for practically every credit scenario, at which the installments completely repay the loan balance. In the example, a loan of $10,000 with monthly installments of only $1 pays off within 10 years, assuming an interest rate of -70%. Unfortunately, it will be difficult to find lenders on such terms.

References

Mortgage Loans: Wikipedia.org

Amortization calculator: Wikipedia.org

Similar Computations

Installment loan calculators in German: zinseszins.de


Published: November 17, 2021
Updated: August 21, 2022

Mathematical Economics
Economics, Statistics and Calculators