Repayment Calculator
Your loan repayment is the amount borrowed plus interest spread evenly across the term, so a lower rate or shorter term means less interest overall. Enter your loan, rate and term to see the repayment, total interest and schedule.
See it two ways at once: the regular repayment needed to clear a loan in a set time, or how long a fixed repayment you can afford will take to pay a loan off. Choose any compounding and payment frequency, then read off the total interest, a principal-vs-interest chart and a full amortization schedule. Switch to weekly, fortnightly or accelerated payments to see how much interest you save and how much sooner the loan is repaid.
Works for any loan and any currency — a home loan, car loan or personal loan. Enter your own balance, rate and frequencies. Estimates only, not financial advice.
Pick a mode — fixed time or fixed installment — set your balance, rate and frequencies, then press Calculate.
Where your money goes
Amortization schedule
See how every repayment is split between interest and principal, and how your balance falls to zero.
Two ways to plan a loan repayment
This repayment calculator works in the two directions people actually think in. Choose Repay within a fixed time and it finds the regular payment that clears your balance in the years and months you pick. Choose Repay with a fixed installment and it does the reverse — it tells you how long a payment you can afford will take to clear the loan. Either way you get the total interest, a principal-versus-interest chart and the full amortization schedule.
Compounding and payment frequency
Interest can be compounded on a different cycle from the one you pay on. The calculator first turns your quoted rate into an effective annual rate using the compounding cycle, then converts that into the exact rate for each payment period — so monthly, fortnightly, weekly or any other schedule all line up correctly. For most loans, leaving both on their usual monthly setting is right; change them only if your lender states otherwise. To compare a brand-new loan or a refinance, the mortgage calculator and refinance calculator go further.
Estimates only — not financial advice. Your lender may apply fees or rounding that shift the exact figures.
The repayment formula
No black box — here is the exact path this calculator takes from your inputs to the answer. The step most repayment tools quietly skip is the first one, turning a quoted rate into the rate for a single payment period; get that right and the rest is the standard annuity maths.
Step 1 — rate for one payment period
- r annual interest rate (as a decimal)
- c compounding periods per year
- p payments per year
Compound and pay on the same cycle and this collapses to i = r/c. A 9% loan compounded and paid monthly gives i = 0.09/12 = 0.0075.
Step 2 — fix the time, solve for the payment
- M payment each period
- B loan balance
- N total number of payments
Step 3 — fix the payment, solve for the time
The same equation rearranged — so a payment you can afford tells you how long the loan will run.
Worked example — $21,000 at 9%, compounded and paid monthly, repaying $180 a month:
i = 0.09 / 12 = 0.0075
N = −ln(1 − 21000 × 0.0075 / 180) / ln(1.0075) = 278.3 payments
278.3 payments → 23 years, 2.3 months (279 actual payments)
total repaid = $50,093.65, of which interest = $29,093.65
Which loans this works for
Any loan repaid in regular instalments — the maths does not care about the label. The four you will meet most often:
- Mortgages are usually repaid monthly at a fixed rate, so the payment stays level for the whole term; you can choose to pay more than required, but not less. For property tax, insurance and overpayments, the mortgage calculator goes deeper.
- Auto loans work the same way — fixed monthly repayments over a shorter term. The auto loan calculator adds trade-in and sales-tax handling.
- Student loans often start after a grace period and, for federal borrowers, offer income-based plans this simple tool does not model; read the result as the plain amortised cost of the debt.
- Credit cards are revolving credit with no fixed term, so a payoff plan suits them better than a fixed schedule — the debt payoff calculator is built for that.
Ways to clear a loan sooner
Pay a little extra. With no prepayment penalty, anything above the required amount goes straight onto the principal, so the balance — and the interest it keeps earning — falls faster. Try the fixed installment mode with a higher figure to watch the payoff time drop.
Switch to fortnightly. Paying half the monthly amount every two weeks slips one extra month's worth of payments into each year (26 half-payments), shaving time and interest off the loan. Set Pay Back to “every 2 weeks” to model it.
Refinance. Swapping to a shorter or cheaper loan can save real money, but there are upfront fees to earn back first — the refinance calculator works out that break-even point.
Clearing debt early feels good, but it is not always the smartest use of cash. An emergency fund, an employer pension match, or investments that out-earn a low loan rate can all matter more than overpaying.
How to use it & key terms
Enter the loan amount, interest rate and term, then press Calculate for your repayment and a full amortization schedule.
| Term | What it means |
|---|---|
| Principal | The amount borrowed. |
| Interest rate | The yearly cost of the loan. |
| Term | The repayment length; shorter means higher payments but less total interest. |
| Amortization | The schedule showing each payment's interest and principal split. |
| Repayment | A payment that clears interest and part of the principal each period. |
| Total interest | Everything you pay on top of the amount borrowed. |
Sources & methodology
The quoted annual rate is converted to an effective annual rate from the compounding frequency — (1 + rate ÷ c)c − 1 for c compounds a year, or erate − 1 when compounding is continuous — and then to a per-payment rate, (1 + EAR)1/p − 1, for p payments a year. From there it is the standard annuity maths: a fixed time gives the payment B·i ÷ (1 − (1 + i)−N), and a fixed installment gives the number of payments −ln(1 − B·i ÷ P) ÷ ln(1 + i). The schedule is then built one payment at a time, with the final payment trimmed to clear the balance exactly.
Sources: Standard time-value-of-money annuity formulas; effective-rate conversion between compounding and payment frequencies.
Fixed and variable rates, and what they mean for your plan
This calculator assumes a single interest rate for the life of the loan, which is exactly how a fixed-rate loan behaves. In the real world, though, the rate on a loan comes in two broad shapes — fixed and variable — and the difference changes how much certainty your repayment plan really has. Knowing which you hold, and how it is scheduled to move, is the difference between a plan you can trust and an estimate that may drift.
A fixed rate stays the same for the whole term, so the payment you calculate today is the payment you will make every period until the loan clears. That makes budgeting simple and protects you if market rates rise, which is why fixed loans suit long commitments. The trade-off is that if rates fall you keep paying the older, higher rate unless you refinance. For planning, a fixed rate means the numbers this tool produces should hold steady from start to finish.
A variable rate moves with a benchmark, so the payment can rise or fall over time. When you model a variable loan here, treat the result as a snapshot at today's rate rather than a promise. A sensible habit is to run the calculation twice — once at your current rate and once at a higher one — to see how far the payment and total interest would climb if the benchmark rose. If the higher figure would strain your budget, that is worth knowing before you borrow, not after.
Two other features shape the plan as much as the rate. The first is whether the loan is secured, like a mortgage or car loan, or unsecured, like most personal loans; secured debt is usually cheaper because the lender can claim the asset, while unsecured debt costs more for the freedom. The second is whether early repayment carries a penalty, which can blunt the benefit of paying ahead. Because every extra payment lands entirely on the balance, clearing a loan sooner still saves interest — our amortization calculator shows exactly how each payment splits between interest and principal over time.
Frequently asked questions
What does this repayment calculator do?
It solves a loan two ways: it finds the regular payment that clears your balance in a chosen time, or it works out how long a fixed payment you enter will take to pay the loan off. Both give you total interest and a full amortization schedule.
What's the difference between "fixed time" and "fixed installment"?
Fixed time starts from how long you want to take and returns the payment needed. Fixed installment starts from a payment you can afford and returns how long it will take. Pick whichever number you already know.
What does the Compound setting change?
It sets how often interest is added to the balance. More frequent compounding raises the effective rate slightly. “Monthly (APR)” is the usual setting for home loans; “Annually (APY)” treats the rate you enter as already effective.
Why can compounding and payment frequency differ?
Because some loans are quoted on one cycle but paid on another. The calculator converts the rate to an effective annual rate, then to the exact rate for your payment period, so any mix of the two stays accurate.
What is the amortization schedule?
It is a table of every payment, showing how much is interest, how much is principal, and the balance left afterwards. Use the annual view for a per-year summary or the full view for every single payment.
Can I use it for any loan or currency?
Yes. Home loan, car loan or personal loan, in any currency — the maths is identical. The currency symbol is only a label.
How do weekly or fortnightly payments save interest?
Paying weekly or fortnightly instead of monthly slips a little extra principal in each year — fortnightly payments make 26 half-payments, the equivalent of 13 monthly payments instead of 12, so the balance falls faster, lowering total interest and shortening the loan. Set the pay-back frequency to weekly or fortnightly to see the saving.