Start with rent you can realistically collect
Use the signed lease or defensible local rent evidence, not a seller’s best-case listing. Multiply monthly rent by twelve, then deduct an allowance for vacancy and collection losses. An occupied property can still face arrears, a turnover gap or a leasing incentive. Keep parking and laundry income separate, and allow for their own losses before entering them.
Do not subtract vacancy twice: if you use actual rent collected for a past year, the vacancy loss is already reflected. For a forward budget, use scheduled rent with an explicit vacancy assumption. Actual and projected results answer different questions.
Build operating costs before adding the mortgage
Include property tax, landlord insurance, condo or strata fees, management, routine repairs, maintenance and owner-paid utilities. Use a recent tax bill, insurance quote and strata documents. Check what a management quote includes: leasing fees and taxes may be additional. Do not add utilities again if a fee already covers them.
Net operating income (NOI) is effective income minus operating expenses, before financing. A replacement reserve for a future roof is a cash-planning allocation, not necessarily a current expense. Keep it below NOI, alongside debt service, when calculating distributable cash. This makes your cap rate comparable without hiding future cash needs.
A first-year example in Canadian dollars
Assume a $650,000 rental with $3,500 monthly scheduled rent. At 5% vacancy, annual rent is $39,900. Operating expenses of $9,000 leave $30,900 NOI. Full mortgage payments of $2,400 a month use $28,800 a year; a $1,200 annual replacement allocation leaves only $900 a year, or $75 a month.
If initial cash is $130,000 down payment, $15,000 closing costs, $5,000 renovations and $10,000 reserves, you have committed $160,000. The $900 annual cash flow represents a 0.5625% pre-tax cash-on-cash return. The cap rate on the purchase price is approximately 4.75%. A positive cap rate therefore does not imply a strong cash return. These numbers are illustrative, not Canadian market averages.
Find break-even rent and test the weak points
With the example’s costs fixed, annual rent before vacancy must cover $39,000 of operating expenses, debt service and reserve allocation. At 5% vacancy, monthly scheduled rent must be approximately $3,421.05 to break even. If management fees vary with rent, recalculate those costs rather than treating all expenses as fixed.
At 10% vacancy the same $3,500 rent leaves a $1,200 annual shortfall. If the mortgage payment rises by $300 a month at renewal, annual cash flow falls by $3,600 to negative $2,700 at the original vacancy assumption. Test these changes separately, then together. A property that works only at full occupancy has little room for surprises.
Turn the estimate into an operating budget
Keep reserves sufficient for your own repair, vacancy and financing risks; there is no universal reserve that makes a purchase safe. Compare actual income and costs with the budget each month. Separate temporary expenses from recurring changes, and update the next twelve months rather than relying on the purchase spreadsheet forever.
Taxable rental income is not the same as cash flow. Mortgage principal consumes cash but is not a rental expense deduction; interest treatment depends on the use of borrowed funds. Capital work may have different treatment from repairs. Ask a Canadian tax adviser about your facts instead of treating this pre-tax model as a tax return.
Sources and review
Reviewed 13 October 2026. Confirm current rules with the relevant authority before acting.
CRA: Rental expenses you can deductFCAC: Renewing your mortgageAfter modelling a purchase, keep rent, costs and loans together to review actual performance. Explore property tracking in Akweno.
