Loan Calculator

What Loan Calculator helps you do

See the monthly payment, total interest, extra-payment savings and a full amortization schedule, not just a single payment figure. The schedule shows how each payment splits between principal and interest over the term. Extra monthly or one-time payments are rolled into the same simulation.

Loan calculations run in your browser and your numbers are not uploaded to Haivix.

How it works

These calculators apply standard finance formulas to the numbers you enter. Loans use the reducing-balance annuity formula, where the monthly rate is the annual rate divided by twelve and each payment covers that month's interest before reducing principal. Savings projections compound at the same monthly rate and treat contributions as arriving at the end of each period. Amounts are rounded to the currency's minor unit, with the final payment adjusted so the balance reaches zero. Nothing is fetched from a bank, credit bureau or rate feed, so the result is only as good as the inputs.

How to use Loan Calculator

1. Enter the loan amount, annual rate and term.
2. Choose years or months for the duration.
3. Add any extra monthly or one-time payments you plan to make.
4. Review the payment, total interest and amortization table.

When to use it

• Compare the total cost of two loan offers at different rates.
• See how much interest an extra monthly payment saves.
• Understand how much of an early payment goes to interest.
• Check the effect of a one-time lump-sum payment.
• Prepare a repayment plan before applying.
• Verify a lender's quoted monthly payment.

When not to use it

• Do not use it for a variable-rate loan without re-running at each new rate.
• Do not treat the result as a lender disclosure; fees differ.
• Do not use it for interest-only or balloon structures.

Example

A 250,000 loan at 7.5% over 20 years has a monthly payment of about 2,014 before extras. Total interest is roughly 233,000 over the term. Adding 200 a month shortens the payoff and reduces total interest; the table shows the balance falling faster after the extra is applied.

What you can do with Loan Calculator

• Calculate a reducing-balance monthly payment.
• Accept a term in years or months.
• Model extra monthly and one-time payments.
• Show total principal, interest and amount paid.
• Show months saved and interest saved.
• Export the amortization schedule as CSV.

Example: compare total cost, not just the monthly figure

Check whether the quoted rate is flat or reducing. The same headline percentage can cost very differently depending on how interest is charged.

Confirm the term unit. A duration entered in months instead of years changes the payment by an order of magnitude.

Look at total interest as well as the monthly payment. A longer term lowers the payment and raises the total cost.

Model one extra payment rather than assuming it. The amortization table shows how much of the saving comes from principal versus a shorter term.

Treat the output as an estimate. Fees, insurance, taxes, variable rates and lender rounding can all move the real figure.

Do not treat a calculator as financial advice. For a binding quote, use the lender's own disclosure.

Check the currency and its minor units. The math is currency-agnostic, but formatting, rounding and the number of decimal places change the displayed result.

Write down the rate, term and assumptions you used. A later comparison is only meaningful if both runs share the same basis.

What to know before you start

• Results assume a fixed rate; variable-rate loans change over time.
• Fees, insurance and lender-specific rounding are not included, so a lender quote may differ slightly.
• The schedule is monthly and uses a constant rate.
• Early repayment penalties are not modelled.

Common mistakes

• Entering the term in months while the unit is set to years.
• Forgetting that the one-time extra applies in a chosen month.
• Comparing monthly payments without comparing total interest.
• Assuming a fixed rate will stay fixed for a variable loan.

Troubleshooting

If the payment is rejected as too small, it may not cover the first month's interest.

If the term is capped, the schedule limit is 600 months.

If a one-time payment seems ignored, check its month number.

If the payoff date is wrong, check the start date field.

Related standards and documentation

• ISO 4217 defines currency codes and minor units.
• US Truth in Lending (Regulation Z) governs APR disclosure for consumer credit.
• The EU Consumer Credit Directive (2008/48/EC) defines the annual percentage rate of charge.
• The standard annuity formula relates principal, periodic rate, payment and number of periods.
• ISO 8601 defines the date and duration formats used by the schedule.