About this tool
A loan calculator takes the loan amount, annual interest rate and term, then computes the monthly payment, total interest and total repayment — useful for mortgages, car loans and consumer loans. It supports the two common methods: equal payment (a fixed amount every month) and equal principal (a fixed principal each month with shrinking interest, so you pay more early on).
The equal-payment figure comes from the standard annuity formula: convert the annual rate to a monthly rate i over n periods, then payment = principal × i × (1+i)ⁿ / ((1+i)ⁿ − 1). The tool also produces a month-by-month schedule so you can see how each payment splits between principal and interest. Everything is computed locally in your browser — nothing is uploaded.
How to use
- Enter the total loan amount (principal).
- Enter the annual interest rate (%) and the term in years (or total months).
- Choose a repayment method: equal payment or equal principal.
- Read the monthly payment, total interest and total repayment.
- Expand the schedule to check the principal/interest split of each instalment.
When to use it
- Compare how different mortgage terms change the monthly payment and total interest.
- Weigh equal payment against equal principal to see which fits your cash flow.
- Estimate monthly payments for a car loan or renovation loan.
- Understand the interest breakdown before considering an early partial repayment.
FAQ
What is the difference between equal payment and equal principal?
With equal payment, the monthly amount is fixed: early on most of it is interest, so total interest is higher but payments are steady. With equal principal, you repay the same principal each month and interest falls as the balance drops, so payments start high and decline while total interest is lower. If your cash flow allows, equal principal saves on interest.
Should I enter the annual or monthly rate?
Enter the annual rate; the tool divides it by 12 to get the monthly rate used in the formula. For example, a 4.8% annual rate becomes a 0.4% monthly rate.
Will the result exactly match the bank?
It is usually very close. Real loans may involve floating rates (e.g. benchmark adjustments), daily interest accrual, fees, insurance or different rounding rules, so treat the bank contract as authoritative — this tool is for estimating and comparing.
Can I use it for interest-free or installment plans?
Yes. Set the annual rate to 0 for an interest-free plan, and the monthly payment is simply the principal divided by the number of periods. Note that many "interest-free" plans charge a separate handling fee, so factor that in to see the real cost.