Personal Loan Calculator - Comparison Rate, Extra Repayments

Q: What formula does the calculator use?

It uses the standard loan repayment (PMT) formula: PMT = P × [ r(1+r) n ] ÷ [ (1+r) n − 1 ] P = amount you borrow r = interest rate for one period (yearly rate ÷ number of payments per year) n = total number of repayments The Step-by-Step Solution box shows each number filled in.

Q: What is the difference between total repayments and total cost?

Total repayments = principal + interest. It is the money that goes through your loan account. Total cost = principal + interest + all fees. It is the real amount the loan takes out of your pocket. Always compare loans on total cost.

Commbank Personal Loan Calculator

Updated Aug 25, 2026 By Jehan Wadia

Introduction

This CommBank Personal Loan Calculator shows you what a personal loan will really cost. Type in how much you want to borrow, pick a loan term, and choose how often you want to pay. The calculator works out your repayment right away.

It also shows the total interest, the fees, and the full cost of the loan. You can pick a secured or unsecured loan, add your own interest rate, and see the comparison rate, which includes fees.

With this tool you can:

See your weekly, fortnightly, or monthly repayment with our Loan Payment Calculator
Find out how much interest you pay in total using the Loan Interest Calculator
Add extra repayments to pay the loan off sooner and save money — see the Extra Payment Calculator
View a full repayment schedule and simple charts, just like the Amortization Calculator
Compare two loan options side by side with the Loan Comparison Calculator

Every number comes with a step-by-step working, so you can see how the math is done. Use it to plan your budget before you apply, and check the wider picture with our Budget Calculator.

How to use our CommBank Personal Loan Calculator

Enter your loan amount, term, repayment frequency, loan type and any fees. The personal loan calculator then shows your repayment, total interest, total fees, total cost, a payoff date and a full repayment schedule. If you are looking at other CommBank products, try the Commbank Loan Calculator or the Commbank Home Loan Calculator.

Loan amount: Type how much you want to borrow, from $1,000 to $50,000. You can also drag the slider to set the amount.

Loan term: Pick how long you want to take to pay the loan back, from 1 to 7 years. A shorter term means bigger repayments but less interest. Our Loan Calculator lets you test longer terms too.

Repayment frequency: Choose weekly, fortnightly or monthly. This sets how often you pay and how your repayment is shown. You can also see the same result as a CBA Repayment Calculator style figure.

Loan type: Choose secured or unsecured. Secured loans are backed by an asset, like a car, and get a lower interest rate. For vehicles, compare with the Auto Loan Calculator or the Used Car Loan Calculator.

Loan purpose: Pick what the loan is for, such as a car, renovation or debt consolidation. The tool shows a tip and the security type that usually suits it. If you are rolling several debts together, the Debt Consolidation Calculator is a good next step.

Extra repayment per period: Add any extra money you plan to pay each time. Extra repayments cut your interest and clear the loan sooner — see how much sooner with the Loan Payoff Calculator.

Custom rate: Tick the box to type your own interest rate between 1% and 30% p.a. Leave it off to use the standard secured or unsecured rate. Not sure what rate applies? Use the Loan Interest Rate Calculator.

Establishment fee: Enter the one-off application fee your lender charges to set up the loan.

Monthly account-keeping fee: Enter any fee charged each month to keep the loan open. Put 0 if there is none.

Annual fee: Enter any yearly fee on the loan. Put 0 if there is none.

Affordability check: Click Comfortably, Manageable or Tight. The tool gives you a tip, and may suggest a smaller loan amount. Lenders also look at your debt load, so check your DTI Calculator result before applying.

Scenario B loan amount, term and rate: Enter a second loan to compare. The calculator shows both side by side so you can see which one costs less.

What Is a Personal Loan?

A personal loan is money you borrow from a bank and pay back over a set time. You pay it back in equal amounts, called repayments. Each repayment covers two things: part of the money you borrowed (the principal) and the interest the bank charges you. Personal loans in Australia usually range from $1,000 to $50,000, with terms from 1 to 7 years. If you need a bigger or different type of loan, see the Installment Loan Calculator or the Business Loan Calculator.

Secured vs Unsecured Loans

A secured loan is backed by something you own, like a car. If you stop paying, the bank can take that item. Because there is less risk for the bank, the interest rate is lower. An unsecured loan is not backed by anything, so the rate is higher. Car loans are often secured — the Car Loan Amortization Calculator shows how those work. Loans for travel, weddings, or bills are usually unsecured. Other secured options include a Motorcycle Loan Calculator, Boat Loan Calculator and Home Equity Loan Calculator.

Interest Rate and Comparison Rate

The interest rate is the yearly cost of borrowing, shown as a percent (p.a. means "per year"). The comparison rate is a better guide to the true cost, because it adds fees to the interest rate. In Australia, lenders must show it based on a $30,000 loan over 5 years. Always compare loans using the comparison rate, not just the interest rate. It works much like an APR Calculator, and you can also check the Effective Interest Rate Calculator.

Fees to Watch For

Establishment fee: a one-off fee to set up the loan.
Monthly account-keeping fee: a small fee charged every month.
Annual fee: a yearly fee on some loans.

Small fees add up. A $10 monthly fee over 5 years costs $600.

How the Loan Term Changes Your Cost

A short term means bigger repayments but less total interest. A long term means smaller repayments but more total interest. For example, the same loan over 7 years can cost hundreds more in interest than over 3 years, even at the same rate. Run both through the CBA Loan Repayment Calculator to see the gap in dollars.

Repayment Frequency

You can often pay weekly, fortnightly, or monthly. Paying weekly or fortnightly cuts your balance a little faster, so you pay slightly less interest overall. Pick the one that matches your pay cycle — our Paycheck Calculator can help you line the two up.

Extra Repayments Save Money

Paying a bit more than you need to goes straight onto the principal. That lowers the balance interest is charged on, so you finish the loan sooner and pay less interest. Even $20 extra each month can make a real difference — see the effect with the Early Payoff Calculator. Check that your loan allows free extra repayments, as some fixed-rate loans charge a break fee.

Before You Borrow

Make sure the repayment fits your budget with room to spare. Add up your income, bills, and other debts first with the Monthly Budget Calculator, and keep some savings aside using the Emergency Fund Calculator. If the repayment feels tight, borrow less or choose a longer term. If you are juggling several debts, the Debt Snowball Calculator and Debt Avalanche Calculator can help you set an order to clear them. Lenders also look at your credit score, income, and existing debts when they decide your rate.

These numbers are estimates only. Your real rate and repayment depend on the lender's assessment of your application.

Formulas used

Periodic interest rate

r = \frac{i_{\text{annual}}\%}{100 \times m}

Number of scheduled repayments

n = t_{\text{years}} \times m

Scheduled repayment (PMT)

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

Repayment when rate is zero

PMT = \frac{P}{n}

Per-period amortisation (interest, principal, balance)

I_k = B_{k-1} \times r, \qquad Pr_k = (PMT + E) - I_k, \qquad B_k = B_{k-1} - Pr_k

Total fees over the life of the loan

F = F_{\text{est}} + f_{\text{monthly}} \times \frac{12\,n_{\text{actual}}}{m} + f_{\text{annual}} \times \frac{n_{\text{actual}}}{m}

Total cost of loan

C = P + \sum I_k + F

Comparison rate (solve for i, $30{,}000 over 5 years monthly)

P_{b} - F_{\text{est}} = \left(PMT_{b} + f_{\text{monthly}} + \frac{f_{\text{annual}}}{12}\right) \times \frac{1-(1+i)^{-60}}{i}, \qquad \text{Comparison rate} = i \times 12 \times 100\%

Frequently asked questions

Is this calculator run by CommBank?

No. This is a free tool built to model how a CommBank-style personal loan works. It is not owned by or linked to Commonwealth Bank. Rates and fees you enter are your own estimates, so always check the real numbers with the lender before you apply.

How accurate are the results?

The math is exact for the numbers you type in. But the results are still an estimate, because:

Your real rate depends on your credit check and income.
Lenders may round repayments to the nearest cent or dollar.
Some lenders charge interest on daily balances, not per period.

Expect your real repayment to be within a few dollars of this figure.

What formula does the calculator use?

It uses the standard loan repayment (PMT) formula:

PMT = P × [ r(1+r)ⁿ ] ÷ [ (1+r)ⁿ − 1 ]

P = amount you borrow
r = interest rate for one period (yearly rate ÷ number of payments per year)
n = total number of repayments

The Step-by-Step Solution box shows each number filled in.

Why does my repayment differ from the CommBank website?

Usually because of small input gaps. Check that you have matched:

The exact interest rate (secured or unsecured)
The loan term in years
The repayment frequency
The establishment and monthly fees

Some lenders also add the establishment fee to the loan balance instead of charging it up front, which lifts the repayment slightly.

Does the calculator save or send my information?

No. Everything runs in your browser. Nothing is stored, sent, or shared. There is no application, no credit check, and no effect on your credit score.

Why is the comparison rate higher than the interest rate?

Because it adds fees on top of the interest. The interest rate only shows the cost of the money. The comparison rate rolls in the establishment fee, monthly fee, and annual fee, so it shows the true cost. If you set all fees to $0, the two rates will match.

How does the calculator split a monthly fee across weekly payments?

It spreads the fee evenly. A monthly fee is multiplied by 12 to get the yearly cost, then divided by the number of payments per year. So a $10 monthly fee becomes about $2.31 per week or $4.62 per fortnight. The yearly total stays the same.

Why does most of my early repayment go to interest?

Interest is charged on the balance you still owe. At the start the balance is highest, so the interest slice is biggest. As the balance drops, less goes to interest and more goes to the principal. The repayment schedule shows this shift row by row.

What is the difference between total repayments and total cost?

Total repayments = principal + interest. It is the money that goes through your loan account.

Total cost = principal + interest + all fees. It is the real amount the loan takes out of your pocket. Always compare loans on total cost.

What does the payoff date mean?

It is the date of your final repayment, counting from today. It assumes your first repayment is one period from now and that you never miss one. Extra repayments pull this date forward.

How does the affordability check work?

You click Comfortably, Manageable, or Tight. The tool then gives a tip. If you click Tight, it suggests a loan amount about 15% smaller and shows the new repayment. You can apply that amount with one click. It is a guide only, not advice.

What is Scenario B used for?

It lets you test a second loan next to your first one. Change the amount, term, or rate and the table and chart update. It is handy for comparing a secured rate against an unsecured rate, or 3 years against 5 years. Scenario B uses the same frequency, fees, and extra repayment as Scenario A.

Can I borrow more than $50,000?

Not in this tool. Most Australian personal loans cap out at $50,000, so the slider stops there. For larger amounts you would usually need a secured loan, a home equity loan, or a home loan.

What does the RBA cash rate badge show?

It shows the Reserve Bank of Australia cash rate and how far your loan rate sits above it. The cash rate is the base rate for lending in Australia. Personal loan rates sit well above it because they are riskier for the bank than a home loan.

Can I add extra repayments later instead of from day one?

This tool applies your extra amount to every repayment from the first one. That shows the biggest possible saving. If you start extra payments later, your real saving will be smaller. As a rough test, try a smaller extra amount to see a middle result.

Why did my extra repayment not change anything?

Check two things. First, that the extra box is above $0. Second, that you clicked away from the box so the number registered. Also, very small extras on a short loan may only cut days, not full periods, so the repayment count stays the same.

Does the calculator include insurance, stamp duty, or early exit fees?

No. It only covers the establishment fee, monthly fee, and annual fee. Add-ons like loan protection insurance, car insurance, stamp duty, or break fees for paying early are not included. Ask your lender what else applies.

Should I pick a lower repayment or a shorter term?

It depends on your budget. A shorter term costs less interest overall but takes more from each pay. A longer term is easier week to week but costs more in the end. Pick a term you can meet every time, then use extra repayments to finish early if you can.

Can I hide the repayment schedule?

Yes. Click the Hide full repayment schedule button above the table. Click it again to bring the table back. The rest of the results stay on screen either way.

Why does the calculator say it cannot work out my loan?

That message shows when the numbers do not work, for example if the rate is so high that a repayment would not cover the interest. Lower the rate, raise the loan term, or check the amount you typed. All fees must be zero or higher.