About Calculix.ca
Calculix.ca brings together free financial calculators built for Québec: tips, budgets, investments, NPV and IRR, loan amortization, pay equity and invoices with GST and QST.
Who is behind Calculix.ca
Calculix.ca is designed and maintained by Marie-Pier Pellerin, founder of Solutions Pellerin, a company based in Val-des-Sources (Québec) that specializes in process optimization and business intelligence. Her work involves helping organizations automate their processes and build dashboards (Zoho, Power BI, Excel), and designing training, including Lean Six Sigma, Excel and Power BI courses.
Calculix.ca applies the same approach to everyday questions: start from a precise rule — a discounting formula, an amortization schedule, an expense split, the taxes on an invoice — and turn it into a calculation that is clear, verifiable and free.
Our tools
- 💵 Tip splitting
Equal shares or in proportion to hours worked, with Excel export.
- 📈 Investment projection
Time or amount needed to reach a goal, with compound returns and contributions.
- 📊 NPV and IRR
Net present value, internal rate of return and payback period of a project.
- 🏠 Amortization
Loan or mortgage payments and the principal/interest split, period by period.
- 💑 Couple budget
Sharing joint expenses in proportion to income or by a chosen percentage.
- 👤 Personal budget
Income, expenses, savings rate and the 50/30/20 rule.
- ⚖️ Pay equity
Job class evaluation with weighted factors, based on Québec's Pay Equity Act.
- 🧾 Invoices and receipts
Invoices with GST/QST, HST or no tax, history and printable PDF.
How our calculations are built
- Every calculator is based on a standard formula (compound interest, discounting, amortization) or a published rule, explained below the tool.
- Calculations run entirely in your browser: the amounts and details you enter are neither stored nor transmitted by our calculators.
- Assumptions are shown (constant rate, compounding frequency, rounding) so that you can redo the calculation yourself.
- Results are estimates: a real investment varies with markets, and your financial institution may round or calculate differently.
Official sources
Updates and corrections
Rules change: public plan parameters, rates, public holidays, laws. We review the tools when those rules change. If you spot an error or a case that is handled poorly, write to info@calculix.ca with the values you entered and the result you expected: every report is checked and corrected where needed.
This page was last reviewed in November 2026.
An independent site
Calculix.ca is not affiliated with any government department or public agency. Agency names (for example Revenu Québec, the Canada Revenue Agency or the CNESST) are mentioned only to cite the rules and point you to the official source.
Disclaimer
Partnerships and affiliation
Contact
A question, an idea for a new tool or an error to report? Write to info@calculix.ca.
Solutions Pellerin — Marie-Pier Pellerin
Val-des-Sources (Québec), Canada
