Offset Mortgage Calculator Demo/Tutorial

The Offset Mortgage Calculator is a built-in Broki tool designed to help brokers clearly explain the real-world value of offset-style mortgage products — like Manulife One — to their clients. It goes further than any other calculator on the market by running three scenarios simultaneously and showing clients exactly where their savings are actually coming from.

Most existing calculators (including Manulife's own) produce large, impressive savings numbers by comparing a client who does nothing against a client who applies 100% of their surplus income to the mortgage — but they credit all of those savings to the product itself. Broki's calculator separates those two things so a broker can have an honest conversation with their client and show them the true value of the offset structure specifically.

The end result is a shareable, broker-branded client report that can be generated in seconds and walked through with the client directly.

When competing on rate, an offset mortgage product like Manulife One will almost always look more expensive on paper. The rate is typically higher than a discounted variable or fixed mortgage from a major lender, and there is a monthly admin fee on top.

What those rate comparisons miss is that the offset structure allows every dollar of income to reduce the balance that interest is calculated on — every single day. A client who deposits their paycheque into the account, pays their bills from it, and lets their surplus sit there is naturally applying their cash flow toward their mortgage without any extra effort or discipline.

The problem is that other calculators don't distinguish between:

Broki's calculator shows both — and then shows what happens when discipline slips. This gives brokers a powerful, honest tool to explain the product and qualify whether it's actually the right fit for a given client.

Every calculation runs three scenarios simultaneously and compares their total interest paid over the same time horizon:

Scenario A — Status Quo The client continues making only their contracted mortgage payments with no extra effort. Their surplus income sits in a savings account earning approximately 1.5%. This is what Manulife's calculator calls the "Current Way."

Scenario B — Disciplined Traditional The client applies their monthly surplus as prepayments against a traditional discounted variable or fixed mortgage, within the standard 20% annual prepayment privilege. This scenario is what Broki shows that Manulife does not. It answers the question: what if the client did the exact same thing but with a regular mortgage instead?

Scenario C — Manulife One / Offset Style The client deposits all income into the offset account, pays expenses from it, and lets their surplus naturally reduce the revolving balance. Interest is calculated daily on whatever balance remains. The calculation also accounts for:

The gap between Scenario A and Scenario C is what Manulife shows as your "total savings." The gap between Scenario B and Scenario C is the true marginal benefit of the offset product itself. Broki shows both, clearly labelled.

Interest on the offset Main Account is calculated on the average daily balance using the Manulife One Base Rate (currently 4.95%), compounded monthly:

Monthly interest = Average daily balance × (Base rate ÷ 12)

The average daily balance is approximated as the midpoint between the opening and closing balance for the month — accurate to within 0.5% of true daily compounding over a 25-year horizon.

Interest on the traditional mortgage uses the Canadian standard semi-annual compounding formula. The equivalent monthly periodic rate is:

Monthly rate = (1 + nominal rate ÷ 2)^(1/6) − 1

This ensures a true apples-to-apples comparison, since Manulife One's monthly compounding is slightly more expensive than a semi-annually compounded rate at the same posted number.

Prepayment privilege cap for Scenario B is set to 20% of the original principal per year — the typical Big-5 bank allowance. The calculator enforces this cap monthly, holding any overage in savings until the next year.

Day-1 savings deposit is subtracted from the Manulife One starting balance before the first month runs. This reflects the real benefit of moving existing savings out of a 1.5% HISA and into an account that offsets 4.95% debt. The rate difference on those savings is broken out as its own line item in the attribution breakdown.

Debt consolidation is handled by folding any entered debts (credit card, auto loan, LOC, etc.) into the Manulife One balance from day one at the lower offset rate. In Scenario A, each debt continues on its own original rate and minimum payment. The interest savings from the rate difference are real and shown separately.

Sub-account amortization runs separately from the Main Account. The portion above 65% LTV (which Manulife One requires to be placed in a fixed sub-account) is amortised at the locked fixed rate on its own payment schedule, completely independently of the revolving surplus paydown.

After the simulation runs, the calculator decomposes the Manulife One advantage into its causal components so the client can see exactly where the savings are coming from:

All components are required to sum to the actual difference in total interest paid between Scenario B and Scenario C within ±$50. This is the most important integrity check in the calculator.

One of Broki's key improvements over Manulife's own calculator is the sub-account recommendation. Rather than asking the client to figure out how to split their balance, the calculator recommends the optimal structure based on their specific balance, surplus, and amortization.

How the recommendation is made:

The calculator first determines the required sub-account amount — the portion of the balance above 65% of the home value, which Manulife One requires to be placed in a fixed-rate sub-account.

For any balance at or below 65% LTV, the recommendation depends on the client's surplus. If their monthly surplus is high relative to their balance, keeping more in the revolving Main Account lets them pay it down faster using their cash flow. If they have limited surplus or are concerned about rate risk, locking a larger portion at a lower fixed rate reduces exposure and provides a predictable payment.

The calculator then runs mini-simulations for the recommended split, a minimum-required split, and a 50/50 split — and shows the total interest cost of each option side by side so the broker and client can make an informed choice.

Because the calculator defaults to 75% surplus application (not 100% like Manulife's calculator assumes), it also shows what happens when discipline slips. Four scenarios are shown at 100%, 75%, 50%, and 25% surplus application — giving both the broker and client a realistic picture of the range of outcomes.

The break-even discipline threshold is also calculated: the minimum percentage of monthly surplus the client needs to consistently apply in order for the offset mortgage to outperform a traditional mortgage with prepayments. This is a critical number for qualifying a client's suitability for the product.

Enter the client's home value and select their province. The calculator immediately displays the maximum Manulife One borrowing limit (80% of appraised value) as a live hint.

Enter:

Tip from the walkthrough: When comparing against a scenario where the client has been offered a lower rate elsewhere, enter that competing rate here. Even if Manulife One's rate is higher, the offset structure and discipline can often overcome the rate difference — and this is exactly what the calculator will show.

List any debts the client wants to roll into the Manulife One account. For each debt, enter the type (credit card, personal LOC, auto loan, other), the balance, the interest rate, and the minimum monthly payment.

Skip credit cards the client pays off in full every month — these carry no ongoing interest cost and don't belong in this calculation.

You can add as many debt rows as needed. This step is optional — skip it if the client only has their mortgage.

From the walkthrough: A $5,000 credit card debt and a $20,000 auto loan at 6% with a $400 monthly payment were used as an example. When you consolidate these into the Manulife One account, the calculator automatically computes the rate arbitrage savings compared to keeping them on their original rates.

Enter the client's combined monthly take-home income and their monthly lifestyle expenses excluding the mortgage payment and any debts listed in Step 3.

You can enter the expense total as a single number, or use the detailed expense breakdown to build it up category by category:

The calculator shows the available monthly surplus live as you type. Below it, a slider lets you set the realistic surplus application rate — defaulting to 75%. Drag this lower for clients who are less disciplined with their spending, or higher if they are committed to maximising paydown.

Important note from the walkthrough: Manulife's own calculator assumes 100% of the surplus goes toward the mortgage forever. In practice, that almost never happens with a traditional mortgage because the client has to consciously make extra payments. With Manulife One, the offset structure makes this natural — money just lives in the account and the balance is always lower as a result. This is actually a key selling point: it's much easier to be disciplined with an offset account than a traditional one.

Enter any savings the client plans to move into the Manulife One account on the day it's funded:

The calculator totals these and shows the immediate impact: the starting balance drops by the full deposit amount, reducing interest from day one. The difference between earning 1.5% in a HISA versus offsetting 4.95% debt is broken out clearly.

From the walkthrough: $10,000 in savings and $15,000 in chequing was used as the example. Moving $25,000 into the account immediately reduces the starting balance by that amount, saving meaningful interest from the first day.

This is where Broki goes beyond Manulife's own calculator. Rather than leaving the client to figure out the structure themselves, the calculator recommends the optimal split between:

Main Account (revolving, variable rate): The flexible portion where income flows in and expenses flow out. Surplus naturally reduces this balance daily.

Sub-account #1 (fixed rate, required above 65% LTV): Any balance above 65% of the home value must be placed here per Manulife's product rules. The calculator defaults to a 5-year fixed rate, which is typically lower than the variable rate, and shows the monthly payment for this tranche.

The recommendation is based on the client's surplus — higher surplus means more benefit from keeping the balance in the revolving account where it can be paid down freely. A fixed sub-account has a predictable payment and rate protection but reduces flexible paydown speed.

From the walkthrough: An example used $200,000 in the fixed term sub-account with the remainder in the revolving portion. The fixed rate in that example was 4.34%, with the revolving portion at 4.95%. The calculator showed the combined cost and compared it against the traditional mortgage alternative.

You can add additional optional sub-accounts for clients who want more rate hedging or who are planning to use the Smith Manoeuvre.

This collapsed section lets you override the default rate assumptions for advanced scenarios:

Most clients won't need to touch these. They're there for brokers running specific rate scenarios or stress-testing assumptions.

At the top of the results, two numbers appear side by side:

From the walkthrough: In one example, Manulife's number was $249,000 in savings. The honest Broki number was approximately $1,770 — a fraction of the headline figure. In another example with consolidated debts, the difference was $101 for the traditional vs offset comparison, against $229,000 versus the status quo. The point isn't that the product is bad — it's that the savings are mostly from the client's behaviour, not the product, and it's important for clients to understand that.

Three horizontal bars show total interest paid across the comparison horizon:

The copy beneath the chart is explicit: the gap between bars 1 and 2 is the client's behaviour. The gap between bars 2 and 3 is what the product actually contributes.

A component-by-component breakdown of the Manulife One advantage showing each positive and negative contributor and their dollar amounts. Clicking any row reveals the calculation behind it.

Shows three numbers: interest saved in year one from the savings deposit, the lifetime compounded impact, and the annual rate arbitrage versus leaving those savings in a HISA. This is a separate panel in Broki not found in Manulife's results.

Compares the recommended structure against alternatives. Shows the total interest cost for each option so the client can see the real cost of choosing a more conservative or more aggressive split.

A line chart showing how total interest paid changes as the surplus application rate moves from 0% to 100%. Two lines — traditional with prepayments and Manulife One — converge and cross at the break-even point.

Below the chart, four scenario cards show the total interest at 100%, 75%, 50%, and 25% discipline. The client's chosen percentage is highlighted.

The break-even discipline percentage tells you and the client exactly how much effort is needed to keep the offset mortgage ahead of a traditional alternative.

An expandable table showing the balance remaining for all three scenarios at years 1, 2, 3, 5, 10, 15, and at the debt-free date for each. A fourth column shows the cumulative interest saved by Manulife One versus the status quo at each point.

Five bullets referencing the client's actual numbers, updating dynamically based on inputs:

One paragraph generated automatically from the calculation result, using one of three templates:

Every recommendation ends with the same disclaimer: "This is an educational illustration. Actual rates, fees, and savings vary. Speak with a licensed mortgage professional before making any decision."

Once the results are displayed, click Generate Report to produce a shareable client report. The report includes:

Broker branding (name, license number, logo, contact information) is applied automatically from the broker's Broki profile — no extra setup needed.

The report is designed to be walked through with the client, not just emailed. Use it as a conversation guide to explain how each scenario differs and what the numbers actually mean for their specific situation.

From the walkthrough: "The best part is you can generate a report out of this to go over with your clients." The numbers are for illustration and educational purposes — they will vary based on the client's actual spending habits, how consistently they apply their surplus, and how market rates move over time.

Results are illustrative only. Actual savings depend on the client's real spending discipline, how consistently they apply surplus income, and how interest rates change over the amortization period.

The discipline assumption matters more than anything else. A client who applies 100% of their surplus achieves very different results from one who applies 50%. The calculator defaults to 75% as a realistic middle ground — not the optimistic 100% that Manulife's own calculator assumes.

The offset advantage is often modest when debts are not being consolidated. For a client with no high-interest debt to consolidate and a strong competing rate offer, the Manulife One advantage over a disciplined traditional mortgage may be small — sometimes less than a few thousand dollars over the full amortization. The calculator will tell you this honestly.

The offset advantage is often significant when consolidating high-rate debt. A client with a credit card balance at 19.99% or an auto loan at 8–9% gets substantial rate arbitrage savings by folding that debt into the Manulife One account from day one. This is typically the largest driver of the product's advantage.

Rates in the calculator must be kept current. The default rates are updated quarterly from manulifebank.ca/current-rates.html. If you are running a scenario where rates have recently changed, verify the defaults in Step 7 — Assumptions match current published rates before generating a report for a client.

Main Account: The revolving, chequing-account-style core of the Manulife One product. The balance fluctuates daily as income flows in and expenses flow out. Limited to 65% of the home's appraised value.

Sub-account: A fixed-rate, locked tranche within Manulife One with its own payment schedule and amortization period. Required for any portion of the balance above 65% LTV. Up to five fixed sub-accounts and fifteen variable sub-accounts are permitted.

Offset mortgage: A mortgage structure where the balance that interest is calculated on is continuously reduced by any funds sitting in the linked account. In Manulife One, interest accrues daily on whatever the Main Account balance is that day.

Float / paycheque parking: The benefit of a client's paycheque sitting in the Main Account between the deposit date and when expenses are paid. Even temporarily, that money lowers the average daily balance and reduces interest.

EAR — Effective Annual Rate: The true yearly cost of borrowing accounting for how often interest compounds. Manulife One compounds monthly; traditional Canadian fixed mortgages compound semi-annually. A fair comparison requires converting both to EAR.

Prepayment privilege: The annual allowance on a closed traditional mortgage to make lump-sum principal payments penalty-free. Typically 10–20% of the original principal per year for major Canadian lenders.

Rate arbitrage: The interest savings achieved by replacing high-rate debt (e.g. 19.99% credit card) with lower-rate debt (4.95% Manulife One Main Account). Often the single largest driver of the offset advantage for clients carrying consumer debt.

Rate premium: The amount by which the Manulife One variable rate exceeds a comparable discounted traditional variable mortgage rate. Currently approximately 50 basis points. This is a real ongoing cost that the calculator factors in explicitly.

Day-1 savings deposit: Existing savings the client transfers into the Main Account when the mortgage is funded. These immediately reduce the starting balance and the interest accruing from day one — a benefit that sitting in a separate HISA does not provide.

Discipline threshold / break-even discipline: The minimum percentage of monthly surplus a client must consistently apply toward debt for the offset mortgage to outperform a traditional mortgage with prepayments. Calculated by the Broki simulator for each client's specific inputs.

For questions about the calculator or to report an unexpected result, contact the Broki support team. If you notice a scenario where the calculation seems off, include the full input set so it can be reviewed and corrected.