Loan & Mortgage Calculator

How Loan Amortization Works

When you take out a fixed-rate mortgage or loan, your monthly payment stays the same for the entire term, but the split between principal and interest shifts dramatically over time. In the early years, the vast majority of each payment goes toward interest. Toward the end of the loan, nearly all of each payment reduces the principal balance.

This is called amortization — from the Latin amortire, meaning “to kill off.” Each payment gradually kills off the debt. The calculator uses the standard PMT formula to compute your monthly payment: 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 total number of monthly payments.

For a $400,000 mortgage at 6% over 25 years, your monthly payment would be approximately $2,577. Over the life of the loan, you'd pay roughly $373,000 in interest — nearly equal to the original loan amount.

Here's the thing: even small extra payments early can save tens of thousands of dollars.

The amortization table below the results shows every year of your loan: how much principal you paid down, how much went to interest, and what balance remains. Use the visual chart to see at a glance how the principal/interest ratio shifts year over year.

Understanding Your Mortgage

A few practical tips to reduce the total cost of your loan:

• Down payment impact: A larger down payment reduces your loan principal directly. In Canada, putting down 20% or more avoids mandatory mortgage default insurance (CMHC), saving thousands in premiums added to your balance.
• Rate vs. term tradeoff: A 15-year mortgage typically has a lower interest rate than a 30-year mortgage, and you pay far less total interest, but the monthly payment is noticeably higher. Compare both scenarios here before deciding.
• Extra payments go straight to principal: If your lender allows lump-sum prepayments, any extra amount reduces the principal immediately and cuts the total interest owed over the remaining term. Even one extra payment per year can cut years off a 25-year mortgage.
• Interest-to-principal ratio: The ratio shown in the results tells you how much you pay in interest for every dollar of principal. A ratio of 0.8 means you pay $0.80 in interest for each $1.00 of principal — a useful quick benchmark when comparing loan offers.
• Refinancing opportunity: If rates drop a lot after you lock in, refinancing can lower your monthly payment or reduce the total interest. Use this calculator to compare your current loan against a hypothetical refinanced version.

Presets, extra payments, and a CSV you can actually use

Four loan-type presets load a typical scenario in one tap: Mortgage 🏡 at 25 years, Auto 🚗 at 5 years, Student 🎓 at 10 years, Personal 💳 at 5 years — each prefilled with a rate in the ballpark of what lenders actually offer. They're a starting point, not a quote. The extra monthly payment field now shows two numbers: total interest saved over the life of the loan, and how many months earlier you'd be done. On a $400,000 mortgage at 6%, adding $300/month cuts roughly 4–5 years off the term. The math is there; you decide if the cash flow tradeoff is worth it.

The full amortization table downloads as a CSV — every month, not just the first 36. Paste it into a spreadsheet to plan an extra lump-sum payment or model a refinancing scenario. The calculator is now fully bilingual too. What it still doesn't do: Canadian semi-annual compounding (the FAQ covers the difference), variable-rate scenarios, or CMHC insurance math. Those are deliberate omissions — this tool answers one question clearly, not ten questions poorly.

When to Use a Loan Calculator

A loan calculator is useful any time money is borrowed with interest. Here are the most common situations:

• Comparing loan offers (car, personal, student) — plug in each lender's rate and term to find the lowest total cost, not just the lowest monthly payment.
• Understanding the true cost — see exactly how much of your total payments is principal vs. interest before you sign anything.
• Planning your budget before applying — confirm the monthly payment fits your income before a hard credit inquiry appears on your file.
• Calculating affordability by income — work backwards from the maximum payment you can afford to find the maximum loan amount you should borrow.
• Checking if extra payments save interest — add a recurring extra monthly amount to see total interest saved and how many months sooner you'd be debt-free.

For deeper analysis, combine this tool with the Compound Interest Calculator, Debt Payoff Calculator, and Savings Goal Calculator to model your full financial picture.

Amortization in Practice: Real Numbers

Each payment splits into two parts: interest (current balance × monthly rate) and principal reduction. Early payments are mostly interest; later payments are mostly principal — this shift is the amortization schedule.

Example — car loan: A $20,000 auto loan at 7% for 60 months gives a monthly payment of approximately $396 and total interest of approximately $3,770. Shorten the term to 48 months and the payment rises to ~$478, but you save roughly $1,000 in interest and own the car a year earlier.

The amortization table this calculator generates shows every year of your loan: how much principal you paid down, how much went to interest, and what balance remains. Use it to identify the exact point where principal reduction overtakes interest, and decide whether extra payments make sense for your situation.

Frequently Asked Questions