Modern Cents — Canadian Mortgage Calculator

Polished scenario modeling with semi-annual interest, lump sums, and renewal projections

Modern Cents is a free Canadian mortgage calculator that models the full cost of your mortgage using semi-annual compounding — the standard required by Canadian law for fixed-rate mortgages. Enter your loan details and instantly see your payment breakdown, total interest paid, and remaining balance at the end of your term.

Key features

• Semi-annual compounding — matches Canada's Interest Act for fixed-rate mortgages
• Multiple payment frequencies — monthly, bi-weekly, weekly, accelerated bi-weekly, and accelerated weekly
• Extra payments & lump sums — model prepayments as a fixed dollar amount or percentage of principal, applied once or every year
• Variable-rate support — enter a prime rate and spread; the effective rate updates automatically
• Scenario comparison — run two scenarios side-by-side to compare rates, frequencies, or prepayment strategies
• Renewal planner — project multiple renewal options from your term-end balance and compare their total cost
• Full amortization schedule — period-by-period table showing payment, interest, principal, and outstanding balance
• Print-ready summary — one-click formatted summary designed for letter-size paper

How Canadian mortgage interest works

Canadian fixed-rate mortgages must compound semi-annually under the Interest Act, not monthly as is common in other countries. This means the stated annual rate is first converted to a semi-annual effective rate, then to an equivalent rate matching your chosen payment frequency. Modern Cents applies this conversion automatically so your results reflect the true cost of borrowing.

For informational purposes only. Not financial advice. Calculations are based on standard Canadian mortgage conventions.