Canadian Mortgage Calculator for ChatGPT and Claude.

Mortgage Tools by Jenny is a set of six Canadian mortgage tools, calculators and short preparation guides, that can be added to ChatGPT, Claude or another AI assistant that supports custom MCP connectors. You add it by pasting its server address into the assistant's connector settings. It is not listed in any assistant's directory, and it is not affiliated with OpenAI or Anthropic.

Mortgage Tools by Jenny is a set of six Canadian mortgage tools, calculators and short preparation guides, that can be added to an AI assistant that supports MCP connectors, such as ChatGPT or Claude. You type your own figures in the conversation and the assistant returns payments, interest, costs and debt left for each scenario. It works only from the rates and terms you supply, in Canadian dollars, and the results are educational scenarios, not advice, approval or a lender quote.

The six tools are: Check missing mortgage facts, Compare mortgage renewal offers, Model extra mortgage payments, Compare breaking or keeping a mortgage, Compare debt consolidation into a mortgage, and Read a mortgage preparation guide.

You add it once as a custom connector by pasting the server address https://mcp.jenny.mortgage/mcp into your assistant's connector settings. There is no sign-in step, so leave any authentication setting at none. After that, ask a mortgage question in a new conversation and the assistant can call the calculators.

See the steps for each assistant.

Yes. Give it two or three offers for the same balance, for example your current lender's renewal letter and a quote to switch lender, and it compares them over a common horizon. It counts the rates, terms, amortizations, cashback and switching costs you supply and returns payments, interest, debt left and a modelled borrowing cost for each offer. A cost you do not know yet is never treated as zero, so the tool will not rank the offers unconditionally until you have it.

The common horizon is the shorter of the terms you supply unless you ask for something else, so a three-year offer and a five-year offer are compared over the same three years. A lower payment on its own does not show a lower cost: the result also shows the debt left at the end of the horizon.

If you would rather work in the browser, use the mortgage renewal calculator on this site. If you are deciding between renewing the same balance and changing the mortgage itself, read renewal or refinance: how the two differ first.

It compares the two paths, but it does not calculate the penalty. You ask your lender for a dated payout quote, and the tool uses that quoted penalty, for example an interest rate differential (IRD) or three months' interest, alongside the replacement offer you supply. It shows cashflow payback separately from the point where total borrowing cost crosses over. If the penalty is still unknown, the result is partial and no option is ranked first.

Cashflow payback is about the cash your household pays out and gets back. Borrowing-cost crossover also counts the debt still owing. The two can give different answers, which is why the result shows both. The document to request is your lender's payout statement for the date you have in mind, with the penalty and any other fees on it.

For how lenders set these charges, read mortgage penalties in Canada.

It compares one mortgage with and without the extras you describe: a higher regular payment, recurring extra payments, or up to 50 lump sums. The result shows interest, debt left and the modelled payoff period for both paths. It checks the extras against your prepayment privilege limits only if you supply them. Otherwise it reports the limits as not checked, and the mathematical result does not confirm that your lender allows the payment without a penalty.

Your mortgage contract sets the limits: how much extra you may pay each time and each year, what the yearly limit is based on and when it resets. Have those, and the date your payment schedule starts, in front of you if you want the tool to check them. A result that runs past the end of your term needs you to state the rate and amortization you want assumed after it, because the tool does not carry an expired rate forward on its own.

Yes, for debts you already have, such as credit-card, car-loan or existing line-of-credit balances. It compares three scenarios over the same horizon: keep the mortgage and the debts, consolidate and pay the new minimum payment, or consolidate and keep the same monthly repayment budget. It shows interest, fees and debt left for each one. A lower payment is not the same as a lower cost, and it does not model a new line of credit, additional cash out or qualification.

You can enter from 1 to 10 debts, each with a fixed monthly payment or as interest-only. This comparison uses monthly mortgage payments. Rolling a debt into a mortgage can stretch its repayment over a longer period and secures it against your home, so look at the debt left in each scenario and not only the payment.

To run a similar comparison in the browser, use the debt consolidation calculator on this site.

The tools themselves need no account, sign-in or email. Your AI assistant has its own account and terms. The figures and labels your assistant sends go to the calculation service so it can compute the answer, and the service does not store them: it has no calculation database and does not write them to its logs. The service sees a network address for each request. To limit abuse, it holds that address in memory with two counts: requests in a 15-minute window, and data sent to that address during the current day (UTC). An expired entry is removed when a later request arrives or when the service restarts, so an address can stay in memory for about a day. When you use an assistant such as ChatGPT or Claude, the request is sent from the provider's network, not from your device. An assistant that connects straight from your own device shows the address your device connects from. The service also writes counters of how often each tool ran and how long calls took, with no figures, labels, network addresses, URLs or headers in them.

See the privacy summary.

The tools do not search or predict rates, calculate a penalty, assess qualification or affordability, model new borrowing or cash out, recommend a lender, or send or contact anyone. The calculations use Canadian mortgage conventions and do not depend on province, so they apply anywhere in Canada. The preparation guides are written for Ontario, and Jenny Tate's own mortgage agent services are available in Ontario only.