Loan amortization schedule calculator with extra payments

Calculator Use

Use this calculator to determine 1) how extra payments can change the term of your loan or 2) how much additional you must pay each month if you want to reduce your loan term by a certain amount of time in months. Try different loan scenarios for affordability or payoff. Create amortization schedules for the new term and payments.

This calculator will provide good results but you may want to also talk to your loan provider to get a calculation from them.

Term Calculation

When investigating different payment amounts (loans with extra payments) you can use the following formula to calculate what your corresponding number of months on the loan will be:

\( n=\dfrac{log\left[\frac{\frac{PMT}{i}}{\frac{PMT}{i}-PV}\right]}{log(1+i)} \)

where n = number of months, PMT = monthly payment, i = monthly interest rate as a decimal (annual rate divided by 100 divided by 12), and PV = loan balance (present value). log is the logarithm base 10.

Payment Calculation

When investigating different terms (months) you can use the following formula to calculate what your corresponding monthly payment amounts will be:

\( PMT=\dfrac{PVi(1+i)^n}{(1+i)^n-1} \)

where n = number of months, PMT = monthly payment, i = monthly interest rate as a decimal (annual rate divided by 100 divided by 12), and PV = loan balance (present value).

Amortization Schedule

• Create printable amortization schedules with due dates
• Calculate loan payment amount or other unknowns
• Supports 9 types of amortization.
• User can set loan date and first payment due date independently.

1. Leave all inputs and setting set to their defaults, and:
   • Enter the "Loan Amount."
   • Enter the expected "Number of Payments."
   • Enter the anticipated "Annual Interest Rate."
   • Set the dates (optional)
2. Set "Payment Amount" to "0" (the unknown).
3. Click either "Calc" or "Print Preview" for your amortization schedule.

That's it! That's all you need to do to create your schedule quickly.

But what if the terms of your loan do not conform to this calculator's default settings?

Then keep reading. I'll explain all the options below. More

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Enter a "0" (zero) for one unknown value above.

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New! Drag & drop your saved files here to load...

File save and open are new beta test features. If you happen to get a different calculated result, do not assume that this calculator is making an error. Most likely, the problem is with the new file load feature. Please check that all settings got loaded as expected.

Always enter (and reenter) a 0 for the unknown value.

Note - You must enter a zero if you want a value calculated.

Why?

Because we want this calculator to create a payment schedule using the loan terms you need. The payment amount can be whatever you want it to be. A payment is "correct" as long as both the lender and debtor agree on the amount! (If the calculator always recalculated the last unknown, then this feature would not be possible.)

TIP - Use an amortization schedule to confirm the periodic interest charges. Interest amounts are the calculations that borrowers should be validating.

Four values you will always need to set:

• Loan Amount - the amount borrowed, i.e., the principal amount. It does not include interest.
• Number of Payments (term) - the length of the loan. The "Payment Frequency" setting also impacts the loan's term. For a term of fifteen years, if the payment frequency is biweekly, you need to enter 390 for the number of payments. (390 biweekly payments = 15 years)
• Annual Interest Rate - the nominal interest rate. This the quoted interest rate for the loan.
• Payment Amount - the amount that is due on each payment due date. For "normal amortization," this includes principal and interest.

Set one of the above to 0 if unknown.

• How do I calculate how much I can borrow?
  1. set the loan amount to zero
  2. enter the number of payments
  3. enter the annual interest rate, and
  4. enter the expected or desired payment
  5. click "Calc" or "Print Preview"

• How do I calculate how long it will take to pay off a loan?
  1. enter the loan amount
  2. set the number of payments to zero
  3. enter the annual interest rate, and
  4. enter the expected or desired payment
  5. click "Calc" or "Print Preview"

• What interest rate allows me to pay $500 a month?
  1. enter the loan amount
  2. enter the number of payments
  3. set the annual interest rate to zero, and
  4. enter $500 for the payment amount
  5. click "Calc" or "Print Preview"

About Dates - they may be (or may not be) important (to you):

If you want an estimated schedule, you may skip over this section.

If you want an accurate, to the penny amortization schedule, you should spend a minute or two understanding these options.

• Loan Date - the date the money is available. If the loan is for a vehicle or home, it is also known as the loan's closing date or start date.
• First Payment Due - for leases, it may be the same as the loan date; otherwise, loan payments will usually start sometime after the borrower has had access to the loan proceeds.

Important - Selecting dates will result in interest charges as well as payment calculations that do not match other calculators.

And that's the point!

However, if you want to match other calculators, then set the "Loan Date" and "First Payment Due" so that the time between them equals one full period as set by "Payment Frequency."

Example: If April 10th is the "Loan Date" and the "Payment Frequency" is "Monthly," then set the "First Payment Due" to May 10th, that is if you want an estimated interest calculation.

More details about the settings available for odd day and irregular period interest.

Four loan options you most likely don't need to touch.

• Payment Period or Frequency - how often do you want to schedule payments? The calculator supports 11 options, including biweekly, monthly, and semiannual (useful for bond coupon interest schedules). The schedule calculates the payment dates from the first payment due date (not the loan date).
• Compounding Period or Frequency - usually, the compounding frequency should be set to the same setting as the payment frequency. Doing so results in simple, periodic interest. Setting this option to "Exact/Simple" results in simple, exact day interest.
• Points - one point is one percent of the loan amount. Points are generally applicable to U.S. mortgages. More about loan schedules with points, fees, and APR support.
• Amortization Method - leave this setting set to "normal" unless you have a specific reason for setting it otherwise. For a complete explanation of these options, see Nine Loan Amortization Methods.

Five loan options you may want to tweak.

These options are available by clicking on "Settings."

• 360 / 365 / 366 - days-per-year option. This setting impacts interest calculations when you set compounding frequency to a day based frequency (daily, exact/simple or continuous) or when there are odd days caused by an initial irregular length period. The 366 days in year option applies to leap years, otherwise the interest calculation uses 365 days.
• Long/Short Period Options - settings for how interest is shown on the schedule when the initial payment period (the time between the loan date and first payment date) is longer or shorter than the selected payment frequency. Click for more details and examples.
• Last Period Rounding Options - due to payment and interest rounding each pay period (for example, payment or interest might calculate to 345.0457, but a schedule will round the value to 345.05), almost all loan schedules need a final rounding adjustment to bring the balance to "0". A footnote on the payment schedule informs you of the rounding amount.
• Points, Charges, & APR Options - see loan schedules with points, fees, and APR support.
• Year-End Month - this setting establishes after what month the calculator shows year-end and running totals. This option is to accommodate businesses with fiscal year ends that do not coincide with the calendar year-end.

Printing the Payment Schedule

Printing will work from any type of device. It's pretty cool to print a well-formatted schedule from a smartphone that is connected wirelessly to a modern printer. (I've personally tested this using an iPhone 5 and iPhone X printing to an HP LaserJet Pro 400.)

Make sure you are printing from the "Print Preview..." window where there are two print buttons available.

If you are using a modern browser, you can print to a PDF as well. For example, if you are using Chrome, click on the menu (the three verticle dots) and select "Print..." Click on the "Change..." button and select "Save as PDF." Other browsers will work similarly.

If you have any problems, please let me know what browser and version you are using. I can test various browsers, but unfortunately, I can't check too many printers (unless you plan to donate one to the cause!).

Beyond Basic Amortization Schedules

Does my amortization schedule change with extra payments?

What happens when you pay extra on an amortized loan?

What does making 2 extra mortgage payments a year do?