Loan repayment calculator
Repayment per week, fortnight or month, with extra payments and the interest you save.
About the loan repayment calculator
Repayment per week, fortnight or month, with extra payments and the interest you save.
Part of SmartCalcy’s finance tools. It runs in your browser with no account, uses your own currency and units (change them at the top of the page), and gives estimates for information only, so check official guidance before you rely on a result.
How to use the loan repayment calculator
What it calculates and when to use it
Calculates loan repayments per week, fortnight, twice a month or month, with extra payments and the interest you save.
How to use it, step by step
- Enter the loan amount, rate and term.
- Choose the repayment frequency.
- Optionally add an extra amount to every payment.
What each input means
- Pay – How often you make payments.
- Extra with each payment – Added on top and applied to principal.
How to read the results
- Repayment – The amount due each period.
- Monthly equivalent – The payment converted to a monthly amount.
- With extra payments – The new payoff time and saving.
The formula
Payment = P × i ÷ (1 − (1 + i)^−n), where i is the yearly rate ÷ payments per year and n is the term × payments per year.
A worked example
25,000 at 7.5% over 5 years paid monthly costs 500.95 a month, 30,057 in total, with 5,057 of interest.
Assumptions and limits
- The rate compounds at the payment frequency.
- Fees and insurance are excluded.
Common mistakes
- Assuming weekly payments save a lot. They only help when payments are smaller than a monthly instalment.
Frequently asked questions
Is it cheaper to pay fortnightly?
Slightly, because interest is charged on a balance that falls more often, but check how your lender calculates interest.
Related tools
Details
- Total interest
- £5,056.92
- Monthly equivalent
- £500.95
Year by year
| Year | Principal | Interest | Balance |
|---|---|---|---|
| 1 | £4,282 | £1,730 | £20,718 |
| 2 | £4,614 | £1,397 | £16,104 |
| 3 | £4,972 | £1,039 | £11,132 |
| 4 | £5,358 | £653 | £5,774 |
| 5 | £5,774 | £237 | £0 |