Loan Payment Calculator
Enter amount, rate and term to compare monthly payments and total interest for amortizing, equal-principal and interest-only loans, with a grace period option.
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Loan Payment Calculator: complete guide
Walk through the steps and examples, or jump straight to the topic you need.
At a glance
- Repayment methods
- Three: equal installments, equal principal and interest-only (balloon).
- Limit
- Terms of up to 600 months are calculated.
- Rounding
- Each installment is cut to a whole won and the leftover change is settled on the last installment.
- Check
- Confirms and shows that the repaid principal adds up to the loan amount.
- Table
- Shows the first and last three installments and omits the middle.
- Comparison
- Calculates the three methods together under the same terms.
- Not included
- Early repayment fees, stamp duty and guarantee fees are left out.
- What it does not do
- It does not recommend products or judge whether you can get a loan.
How to use Loan Payment Calculator
Enter the amount, interest rate and term
You can put commas in the loan amount. Enter the annual interest rate exactly as your bank gave it. Enter the term in months; 5 years is 60. Invalid values are not calculated and the reason is shown.
Choose a repayment method
Choose equal installments if you want to pay the same amount every month; equal principal if you want to cut total interest and can handle the first month's burden; and interest-only (balloon) if you plan to pay only interest for now and repay in a lump sum later. A description of the chosen method appears below.
Check the amounts for each installment
You get the first and last installments, total interest and total repayment. The table shows the first and last three installments and notes how many installments in the middle are omitted. It also checks that the balance reaches 0 on the last installment.
Compare the three methods
The comparison table below shows the three methods side by side under the same terms. The principal is the same for all and only the interest differs. Look at the first installment's burden and the total interest together, and choose between what you can afford now and the total cost.
What it’s good for
The balance reaches 0 on the last installment
If every installment is cut to a whole won, leftover change builds up and the balance ends a few won over or short at the end. This tool adjusts the last installment to repay the remaining principal exactly, so the balance lands on exactly 0. It also checks that the repaid principal adds up to the loan amount and shows that on screen.
The burden comes at different times for each method
Equal principal is the heaviest in the first month but has the lowest total interest. Interest-only (balloon) pays only interest each month and repays the principal in one lump at the end, so it has the highest total interest. Equal installments is in between. The principal is the same in all three methods and only the interest differs, so choose between what you can afford now and the total cost.
Worked examples
KRW 10,000,000 · 6% a year · 12 months
Equal installmentsKRW 860,664 a month
Total interest KRW 327,968Same terms · interest-only (balloon)
Interest-only (balloon)Interest of KRW 50,000 a month
Last installment KRW 10,050,000The difference among the three methods
Swipe the table sideways to see the rest.
| Method | First installment | Total interest |
|---|---|---|
| Equal principal | Highest | Lowest |
| Equal installments | In between | In between |
| Interest-only (balloon) | Lowest | Highest |
When the result isn’t what you expected
It is a few won different from my bank
Banks differ in the reference date for interest and in rounding. This tool calculates by month. If the difference is large, first check whether your rate is an annual rate or a monthly rate.
Only the last installment is different
That is normal. The change left over from cutting each installment to a whole won is settled on the last installment. That is what makes the balance exactly 0.
It will not calculate even though I entered a term
The term must be a whole number. Do not enter 1.5 years; enter the number of months, such as 18.
I want to enter a grace period
Enter the number of interest-only months in the Grace period (months) field. During that period you pay only interest, and the schedule then repays the principal over the remaining months with the method you chose. Interest-only (balloon) already pays only interest until the end, so a grace period does not apply to it.
Key terms
- Equal installments
- A method where the total paid each month is the same. Early on, the share of interest is large.
- Equal principal
- A method where the principal repaid each month is the same. The payment goes down over time.
- Interest-only (balloon)
- A method where you pay only interest and repay the principal in one lump at the end.
- Grace period
- A period when you pay only interest without repaying principal.
Loan Payment Calculator FAQ
Does it calculate early repayment fees?
They are not included. Extra costs such as stamp duty and guarantee fees are left out too. What you actually pay out can be a little more than this calculation.
It is a few won different from the amount my bank gave me
Banks differ slightly in the date basis they use to calculate interest and in how they round. This tool calculates by month, so there can be differences depending on the actual repayment date.
Does it tell me which product is better?
No. It only calculates amounts from the terms you enter. It does not recommend products or judge whether you can get a loan.
Does it calculate variable rates?
It calculates with fixed rates only. If you think the rate may change, try entering a few expected rates and see how much the burden changes.
Can I see every installment?
For now it shows only the first and last three installments, because with many installments the screen would become far too long.
Are my inputs saved?
No. Refreshing returns it to the starting state.