Loan / Mortgage Calculator
Calculate a fully amortised loan in seconds — monthly payment, total interest, total cost and a complete payment schedule. Perfect for mortgages, auto loans, consumer credit and student loans. Supports any currency, any rate and any term up to 40 years.
How to use
- 1
Enter loan amount
Type the principal you plan to borrow.
- 2
Set the rate and term
Pick an annual interest rate and a term in years or months.
- 3
Read the schedule
See monthly payment, total interest and a month-by-month amortisation table.
Technical details
An amortised loan is one where you pay a fixed monthly amount that covers both interest and principal, so the balance reaches zero exactly at the end of the term. Every month, the interest portion is computed on the remaining balance, the rest of the payment reduces the principal, and the next month repeats with a lower balance and therefore lower interest.
The monthly payment formula is `M = P × r × (1+r)^n / ((1+r)^n − 1)`, where P is the principal, r is the monthly interest rate (annual rate / 12) and n is the number of payments (term in months). The total interest paid over the life of the loan is `M × n − P`.
In the early years of a mortgage, most of each payment goes to interest; in the later years, most goes to principal. The calculator shows a complete amortisation table so you can spot the crossover point — typically around year 12 of a 30-year mortgage at 5%.
Making extra payments accelerates the schedule dramatically because each early-paid pound eliminates years of compounded interest. A single extra payment per year on a 30-year mortgage typically shaves 4–5 years off the term.
Frequently asked questions
What is amortisation?
Are fees and insurance included?
Can I model extra payments?
What rate should I enter — APR or nominal?
Will the calculator work for a mortgage?
This tool was tested and calibrated by our engineering team. All processing happens locally in your browser — your files and data never leave your device.