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This calculator provides estimates for informational purposes only and is not an offer of credit. Your actual APR, fees, and payment depend on the lender, your state, and your credit profile.

How to Use the Installment Loan Calculator Online

1F Cash Advance’s installment loan calculator allows you to estimate your monthly payments and the total loan cost based on the amount you want to borrow, repayment period, and the APR you prequalify for or expect to receive. Here’s how it works:

  • Enter the amount you want to borrow

    Installment loans typically range from $1,000 to $50,000. At 1F Cash Advance, lending partners offer installment loans of up to $5,000. The exact amount you can get depends on your income and credit.

  • Choose a loan term

    Enter the number of months within which you expect to repay the loan. Depending on the lender, terms can be from a few months to several years.

  • Enter your expected APR percentage

    Many lenders allow you to prequalify so you can shop for loans and compare offers. When you prequalify, they show you an estimated APR given your application details. If you don’t want to prequalify, check your credit score and enter the average APR offered to borrowers within the same credit spectrum on the loan type you consider (see the table below).

  • Add origination fees, if any

    Some lenders may charge origination fees of 1%–10% of the loan amount. Press “Optional” to include origination fees and enter the exact fee percentage or dollar amount.

  • Click “Check your rate”

    The calculator will show you an estimated monthly payment, total interest paid, and the total amount due (or total cost) based on the information you provided.

Average Personal Loan APRs by Credit

Credit Score 36-Month Loan 60-Month Loan
620 17.97% 18.74%
640 17.21% 17.89%
660 16.12% 17.36%
680 14.76% 15.99%
700 13.19% 14.29%
720 11.97% 13.04%
740 10.82% 11.69%

Source: Curinos data as of September 2026.

Average Auto Loan APRs by Credit

Credit Score New Car Used Car
300–500 16.11% 21.62%
501–600 13.52% 19.10%
601–660 9.71% 13.93%
661–780 6.15% 8.81%
781–850 4.41% 6.29%

Source: Experian data as of Q2 2026; VantageScore 4.0 used.

How to Determine The Monthly Payment for an Installment Loan

While most installment loans have fixed payments, the way they split between the principal and interest changes over the life of your loan. At the start of your loan, the largest share of each payment goes toward interest. Because interest is charged on the remaining balance, its portion in your payment reduces over time as the principal shrinks. That means more money goes toward paying off the principal itself. This process is called amortization.

To calculate your monthly payment, use the standard amortization formula:

$$M = P \times \frac{r(1 + r)^{n}}{(1 + r)^{n}-1}$$

where

  • M – fixed monthly payment,
  • P – your loan principal,
  • r – periodic monthly interest rate (annual interest rate ÷ 12 months),
  • n – the total number of monthly payments over the life of your loan.

To determine what portion goes toward principal and interest, you can use the following formula:

$$\text{Interest payment} = \text{Remaining Balance} \times r$$
$$\text{Principal payment} = M-\text{Interest payment}$$

For each next month, the calculation process repeats with updated remaining balance and interest payment. This happens until the loan is fully paid off.

Representative Example 1

Imagine you take out a $20,000 personal loan with a 5.5% annual interest rate (fixed) for 5 years. Here’s how your monthly payment will be calculated.

1. Find the monthly interest rate (r):

$$\begin{gathered}\text{Annual rate} = 5.5\% \ (\text{or } 0.055) \\[6pt] r = \frac{0.055}{12} = {\sim}0.00458333\end{gathered}$$

2. Find the total number of payments (n):

$$n = 5 \text{ years} \times 12 = 60 \text{ months}$$

3. Plug the numbers into the formula:

$$\begin{gathered}M = 20{,}000 \times \frac{0.00458333(1 + 0.00458333)^{60}}{(1 + 0.00458333)^{60}-1} \\[6pt] M = {\sim}\$382.02 \text{ per month}\end{gathered}$$

The principal and interest portion for the first month is calculated as follows:

$$\text{Interest} = \$20{,}000 \times 0.00458333 = \$91.67$$
$$\begin{aligned}\text{Interest} &= \$20{,}000 \times 0.00458333 \\ &= \$91.67\end{aligned}$$

Principal payment is calculated as the difference between the total monthly payment and the portion of interest paid:

$$\text{Principal payment} = \$382.02-\$91.67 = \$290.35$$
$$\begin{aligned}\text{Principal payment} &= \$382.02-\$91.67 \\ &= \$290.35\end{aligned}$$

For the next month, your remaining balance is:

$$\text{Remaining balance} = \$20{,}000-\$290.35 = \$19{,}709.65$$
$$\begin{aligned}\text{Remaining balance} &= \$20{,}000-\$290.35 \\ &= \$19{,}709.65\end{aligned}$$

Now, your interest and principal portions will split as follows:

$$\begin{gathered}\text{Interest} = \$19{,}709.65 \times 0.00458333 = \$90.34 \\[6pt] \text{Principal payment} = \$382.02-\$90.34 = \$291.68\end{gathered}$$
$$\begin{aligned}\text{Interest} &= \$19{,}709.65 \times 0.00458333 \\ &= \$90.34 \\[8pt] \text{Principal payment} &= \$382.02-\$90.34 \\ &= \$291.68\end{aligned}$$

The remaining balance for the next month’s calculation is:

$$\text{Remaining balance} = \$19{,}709.65-\$291.68 = \$19{,}417.97$$
$$\begin{aligned}\text{Remaining balance} &= \$19{,}709.65-\$291.68 \\ &= \$19{,}417.97\end{aligned}$$

Representative Example 2

The table shows how monthly payments and the total cost of a $5,000 loan change depending on the APR and repayment period:

APR Repayment Term Monthly Payment Total Cost
12% 12 months $444.24 $5,330.93
36% 12 months $502.31 $6,027.73
160% 12 months $857.66 $10,291.95
12% 24 months $235.37 $5,648.82
36% 24 months $295.24 $7,085.69
160% 24 months $701.45 $16,834.88
12% 60 months $111.22 $6,673.33
36% 60 months $180.66 $10,839.89
160% 60 months $667.03 $40,021.92

How to Read Your Amortization Schedule

An amortization schedule is a table outlining each loan payment, with a full breakdown of what goes toward interest and principal over time. Some lenders provide it as a standalone document in your loan paperwork; others offer it on demand, printed or via their online portals. You can also generate one using our installment loans calculator.

An amortization schedule typically consists of six columns:

  1. Payment number from payment one to the end of the loan term
  2. Payment amount
  3. Date of payment
  4. Principal payment (portion of monthly payment amount that goes toward principal)
  5. Interest payment (portion of monthly payment amount that covers interest)
  6. Remaining balance after subtracting your month’s principal payment

Reviewing your amortization schedule can help you track how much of your loan you have actually repaid, how your payments split between interest and principal, and when your next payment is due. You can also test extra payments to see what will happen if you pay more than the minimum. Since any extra payments you make go directly toward your principal, this will help you reduce the remaining balance, save money on interest, and pay off your loan faster.

What Affects Your Loan Payment and Total Cost

Your loan payment and total cost of borrowing depend on six factors:

  • Loan amount. The more you borrow, the higher your monthly payment is likely to be. A larger loan also often means a longer repayment term, accumulating more interest over the life of your loan.
  • Repayment term. Your repayment period determines how many payments you will make before your loan balance turns into $0 and how long interest will be charged. When you borrow for a longer period, it results in lower monthly payments but a higher total loan cost.
  • APR. Your APR may be either fixed or variable, affecting how predictable your payments will be. Fixed APRs do not change over the life of your loan, while variable ones can fluctuate under certain market conditions. Variable rates are usually initially lower but involve risk. The higher the APR, the more you will pay each month and in total.
  • Credit profile. While this parameter doesn’t affect your loan payment and total cost directly, lenders use it to determine what APR you are eligible for. Applicants with good credit typically get lower APRs.
  • Additional fees. Besides fees that are included in your APR, there are also charges that pop up under certain conditions. Examples include late fees, prepayment penalties, insurance fees, and more. If you trigger these fees, they may affect both your payments and total cost.
  • The way you manage repayment. Early repayment can help you save money and pay off your loan faster, while missing payments will increase your total loan cost.

Things to Check Before You Borrow

Borrowing should help you reach your financial goals without straining your budget. Consider the following before you move forward with a lender to ensure your financial journey will be safe:

Whether you can afford payments

Look at how your estimated monthly payments fit into your budget. Make sure you are not overburdened with debts before committing. The standard debt-to-income ratio rule of thumb says that no more than 28% of your gross monthly income should go toward your housing expenses, while 36% or less is considered a healthy, manageable debt level (takes into account both housing expenses and any recurring loan or credit card payments you have).

Your credit score

This parameter determines what APR you should use for calculations, affecting your monthly payments and cost of borrowing. Review your credit reports via AnnualCreditReport.com to understand where your credit score stands and check what APR ranges are typically offered to borrowers with similar credit backgrounds.

Repayment term

Try different repayment periods to estimate monthly payments and the total amount due, then choose the term that balances both.

Final terms

The installment loan calculator provides estimates based on the information you enter. Your actual terms may differ, so review your loan agreement carefully once you get approved. Pay close attention to the APR, repayment period and schedule, payment amounts, and any additional fees hidden in the fine print.

Some loans may come with triple-digit APRs and short repayment terms, making them difficult to manage. Use high-interest loans only as a last resort and make sure you can repay on time to avoid getting into a debt cycle.

Lender’s reputation

Read customer reviews and check how the lender works with complaints. Unresolved issues or repeated negative patterns you see in multiple former borrowers’ reviews are often a red flag.

Types of Installment Loans You Can Calculate

1F Cash Advance’s installment loan calculator can be used for any loans you get in one lump sum and repay in equal monthly installments. These include but are not limited to:

  • Personal loans
  • Auto loans
  • Student loans
  • High-interest installment loans

FAQ

Is the calculator result my actual rate?

The calculator provides only estimates based on the numbers you type. Your actual rate will be determined by your lender based on your credit, income, payment history, and application details.

Does paying early reduce the total interest?

In most cases, yes. Any extra payments you make on your loan go toward your loan principal, reducing the base for interest calculation. Whether you pay off your loan early in full or partially, it will reduce your total interest paid. However, check your loan agreement before making any payments. Some lenders may charge prepayment penalties to recoup lost interest.

What is the monthly payment on a $5,000 loan over 12, 24, or 36 months?

Your monthly payment also depends on the APR. Let’s say you take out a $5,000 loan with an APR of 16%. Your monthly payment on a 12-month loan will be $453.65 ($5,443.85 in total). For a 24-month loan, you will pay $244.82 per month and $5,875.57 in total. If you get the same loan for 36 months, your monthly payment will be $175.79, while the total cost of borrowing will grow to $6,328.27.

Does checking my payment affect my credit score?

No, using a loan calculator does not affect your credit. If you request estimated loan terms from a lender, it may affect your credit if the lender performs a hard credit check at the prequalification stage.