How the loan payment estimator works
The estimator separates two common Canadian rate conventions. Personal and auto loans use a monthly periodic rate in this model, while the fixed-rate mortgage option converts a nominal rate compounded twice per year to an effective monthly rate.
Calculation method
The calculator applies the standard level-payment amortization equation. Each payment covers interest due for the period and reduces principal. The displayed total assumes the rate and payment remain unchanged for the entire amortization, with no fees or extra payments.
Payment = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is principal, r is the periodic rate, and n is the number of monthly payments.Assumptions and counting rules
- Personal or auto loan mode divides the stated annual rate by 12.
- Canadian fixed-rate mortgage mode converts nominal semi-annual compounding to a monthly rate: r = (1 + annual rate ÷ 2)^(1/6) − 1.
- Payments occur monthly and the rate is assumed constant for the entire amortization.
- Fees, insurance, taxes, lender rounding, payment timing, renewals, and prepayments are excluded.
Practical examples
Personal loan comparison
Compare the same principal over three and five years to see the trade-off between monthly payment and total interest.
A longer amortization usually lowers the payment but raises total interest.
Rate stress test
Calculate once at the offered rate and again at a rate two percentage points higher.
This shows whether the budget could absorb a future rate increase.
Canadian mortgage estimate
Choose the mortgage convention when testing a fixed mortgage rate quoted with semi-annual compounding.
Actual mortgage terms may involve renewals before the amortization ends.
Common mistakes
- Confusing the mortgage term with the full amortization period.
- Comparing payments without comparing total interest and fees.
- Assuming the quoted annual rate always converts to a monthly rate by dividing by 12.
- Treating an estimate as a lender disclosure or approval decision.
Edge cases
- At 0% interest, payment is principal divided by the number of payments.
- Very long amortizations can produce low payments but substantially greater total interest.
- Variable rates and renewals cannot be projected accurately with one constant rate.
Questions specific to this tool
Is this a mortgage qualification calculator?
No. It estimates payments only and does not test income, debt-service ratios, stress tests, down payments, insurance, property taxes, or lender criteria.
Why does the mortgage option differ from annual rate divided by 12?
Canadian fixed-rate mortgage disclosures commonly use nominal interest compounded twice per year; converting that convention produces a different effective monthly rate.
Does a lower payment mean a cheaper loan?
Not necessarily. Extending amortization can lower the monthly payment while increasing total interest.
Last reviewed: August 3, 2026 · Method version 1.0.0