Personal Loan Repayment Calculator

Enter your loan amount, interest rate and term to estimate your personal loan repayments and the total interest over the life of the loan. The figures use the same amortised calculation as the rates in our tables. Estimate only, not credit advice.

Loan term

Borrowing $30,000 over 5 years at 9.50% p.a.

Monthly repayment
$630
Fortnightly
$291
Weekly
$145
Total repaid
$37,803
Total interest
$7,803
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Estimate only, based on an amortised principal and interest loan with equal monthly repayments at the rate you entered. Weekly and fortnightly figures are the monthly repayment spread across the year. Actual repayments depend on your rate, fees and loan terms. This is general information, not credit advice.

How we calculate this

The formula

M equals P times r times one plus r, to the power n, all divided by one plus r, to the power n, minus one
M
the repayment due each month
P
the amount borrowed (the principal)
r
the monthly interest rate, which is the annual rate divided by 12
n
the number of monthly repayments, which is the term in years times 12

We then apply:

  • Fortnightly = M × 12 ÷ 26
  • Weekly = M × 12 ÷ 52
  • Total repaid = M × n
  • Total interest = Total repaid − P

What we assume

  • Principal and interest, paid monthly. Every repayment covers the interest charged for the month and chips away at the balance, so the loan reaches zero on the last scheduled repayment. Interest-only periods are not modelled.
  • The rate never changes. The rate you enter is applied for the whole term. A variable rate will move, and a fixed rate reverts to a revert rate at the end of the fixed period, so a real loan almost never runs at one rate for its full life.
  • Fees are excluded. Application, settlement, monthly or annual account fees, valuation fees, discharge fees and lenders mortgage insurance are not included. Compare the comparison rate on a product row to see the effect of fees.
  • No extra repayments, offset or redraw. Paying more than the scheduled amount, or holding savings in an offset account, both cut the interest charged and shorten the term. Neither is modelled here.
  • Weekly and fortnightly are conversions, not schedules. They are the monthly repayment spread across the year (monthly times 12, divided by 52 or 26). Paying weekly or fortnightly on a real loan reduces interest slightly, because the balance falls sooner. Treating them as a straight conversion keeps every figure tied to the one monthly number shown on our product rows.
  • Totals are measured on the monthly schedule. Total repaid is the monthly repayment times the number of months, and total interest is that total less the amount borrowed.

A worked example

A personal loan of $30,000 at 9.50% p.a. over 5 years.

  1. Turn the annual rate into a monthly rate9.50% ÷ 12r = 0.007917
  2. Turn the term into a number of repayments5 years × 12n = 60 months
  3. Work out the growth factor(1 + 0.007917) multiplied by itself 60 timesone plus r, to the power n, equals 1.6050
  4. Put those into the formula$30,000 × 0.007917 × 1.6050 ÷ (1.6050 − 1)M = $630.06 a month
  5. Spread the monthly figure across the year$630.06 × 12 ÷ 26, and × 12 ÷ 52$291 a fortnight, $145 a week
  6. Add up what is paid over the term$630.06 × 60 months$37,803 repaid in total
  7. Take out the amount borrowed to leave the interest$37,803 − $30,000$7,803 of interest

Figures above are rounded for reading, so a line can differ by a dollar from the exact arithmetic. The calculator itself works to full precision.

Borrowing $30,000 at 9.50% p.a. over 5 years costs $630 a month, and $7,803 in interest across the full term.