How this works in your browser
The payment is derived from the standard amortisation formula for a fixed-rate loan, solving for the constant monthly amount that clears the balance exactly across the number of payments. The annual rate is converted to a monthly rate first, which is why a small change in the quoted rate produces a larger change in total cost than intuition suggests on a long term. Total interest is the sum of all payments less the principal. Fees, insurance and origination charges are not modelled, which is precisely the gap between the interest rate you enter and the APR a lender must quote you. Everything is calculated locally.
Loan Calculator vs. typical online calculators
| Feature | Loan Calculator (in-browser) | Typical online calculators |
|---|---|---|
| Where the maths runs | In your browser, on your device | Often posted to a server to compute |
| Your inputs are stored | Never - nothing is sent or saved | Frequently logged with your session |
| Works offline once loaded | Yes | No - needs a live connection |
| Ads inside the result area | None | Common on free calculators |
| Account required | No | Often, to save or export results |
| Usage limits | None - free, unlimited use | Sometimes capped per day |
Who uses Loan Calculator
Comparing car finance offers
See what different rates and terms actually cost across the whole loan.
Budgeting for a personal loan
Check the monthly commitment before applying for anything.
Weighing consolidation
Compare combining debts against keeping them separate.
Checking a quoted payment
Verify a lender's monthly figure against the rate and term they stated.
How to use Loan Calculator
- 1
Open the Loan Calculator
Go to tools.slaytic.com and open the Loan Calculator. No sign-up or account required.
- 2
Enter the loan details
Add the amount, the annual interest rate and the term in months.
- 3
Read the results
You get the monthly payment, total interest and total amount repaid.
- 4
Compare scenarios
Change the term or rate to see how much the total cost moves.
Frequently asked questions
How is this different from the Mortgage Calculator?
This is a general-purpose loan calculator for any fixed-rate loan (auto, personal, etc.) using months as the term unit, while the Mortgage Calculator is specifically tuned for home loans.
Are lender fees included?
No, this estimates principal and interest only. Real loans may include origination fees, insurance, or taxes that increase the actual cost.
Is this financial advice?
No, this is an estimate for informational purposes only. Consult a lender or financial advisor for exact terms.
Why is APR different from the interest rate I entered?
Because APR is designed to include fees as well as interest, giving a comparable figure across lenders. This calculator uses the plain interest rate, so a loan with a low rate and a large origination fee will cost more in reality than the result here suggests. Compare offers on APR, not on rate alone.
Should I take the longer term for a lower payment?
Look at the total interest before deciding. Extending a car loan from three years to six roughly halves the payment while adding a great deal to what the car ultimately costs, and on a depreciating asset it also means owing more than it is worth for longer.
Does overpaying actually help?
Substantially, because interest is charged on the outstanding balance. Any extra payment reduces that balance immediately, so it saves interest on every remaining month. Check for early repayment charges first, as some agreements penalise it.
Are my figures sent anywhere?
No. The calculation runs in your browser, so what you are borrowing and at what rate stays on your device.