First, read the English article below.

You can click the calculator in the "samples" section at the top of this page, then open it with Google Drive, or download it to open with Excel or another spreadsheet program. Alternatively, visit one of the following links:   Bankrate.com and MLCalc are both simple calculators that also show a full table of your payment schedule, including remaining debt.  CalculatorSoup is useful for loans with unusual payment or compounding intervals. For example, Canadian mortgages are typically compounded semi-annually, or twice a year. (The calculators above assume the interest is compounded monthly, and payments are made monthly.) You can make your own loan calculator in Excel, similar to the wikiHow sample above. This is the total amount of money borrowed. If you are calculating a partially paid loan, enter the amount of money you have left to pay. This field may be labeled "base amount." This is the current annual interest rate on your loan, in percentage form. For instance, if you pay a 6% interest rate, type in 6. The compounding interval does not matter here. The interest rate specified should be the nominal annual interest, even if interest is calculated more frequently. This is the amount of time you plan to spend paying off the loan. Use the amount of time specified on the loan conditions to calculate the minimum monthly payment required. Use a shorter amount of time to calculate a higher monthly payment that would pay off the loan sooner.  Paying the loan off sooner will also mean less total money spent. Read the label next to this field to determine whether the calculator uses months or years. This is used to calculate the date when you'll finish paying off the loan. Some calculators will automatically update the "Monthly Payment" field after you enter the information. Others wait until you hit "calculate," then give you a chart or graph showing your payment schedule.  The "Principal" is the amount of the original loan left, while "Interest" is the remaining additional charge. These calculators will display... 

Now, please write a short abstract for it in Vietnamese. Abstract:
Mở một chương trình tính khoản vay phải trả online. Điền số tiền vay. Điền lãi suất. Điền vào thời gian trả lãi. Chọn ngày bắt đầu. Nhấn vào calculate.