Keep the House Calculator (rent it out, or sell it)
New posting. Old house. Two paths. Keep the old posting’s home as a rental — half the rent counts toward qualifying, its whole payment counts against you — or sell it and roll the equity into the next down payment. This calculator runs both paths through the same qualifying math and tells you plainly which one buys more at the new posting.
The old posting’s home
Realtor commission, legal, adjustments — the sale's real haircut.
The new purchase
Not counting the old home — it's added automatically on the keep path.
Keep it — rent it out
$268,857
$1,500/mo of rent counts for you; the old $2,475 payment and $290 tax count against you.
Sell it — roll the equity
$895,137
$300,000 of equity lands on the new down payment.
On these numbers
$626,280
more buying power at the new posting if you SELL — the freed equity does more on the down payment than half the rent does in the ratios. That's not a verdict on keeping a good rental; it's what keeping it costs.
Both paths use the “documented properly” reading at the stress-test rate of 6.79% — same engine as the shift-income qualifier.
The fine print. The 50% rent add-back is the common convention — some lenders count more, some use an offset instead, and WHERE the file is placed changes this answer; that placement is our job. A rental also means vacancies, maintenance, and a tax return with a rental schedule on it — the accountant’s half of the professionals rule. And if the numbers say sell but the market says wait, a conversation about timing beats a formula.
The rules this runs on — and how the math was verified
Both paths run through the same verified affordability engine as the shift-income qualifier — federal stress test (greater of rate + 2% and 5.25%), GDS 39% / TDS 44%, Canadian semi-annual compounding, and the down-payment tiers. KEEP adds 50% of the rent to income and the old home’s payment and property tax to debts; SELL adds the net sale equity to the down payment.
A path with under 20% down is an insured purchase: the insurance premium (2.80% to 4.00% of the mortgage, by how much of the price it covers) is normally added to the mortgage (it can also be paid in one lump sum), and this page assumes it is. The qualifying payment is worked on the mortgage including it, as CMHC requires. A 30-year insured amortization is only for first-time buyers and newly built homes and adds 0.20% to the premium; everyone else is insured over 25 years. With 20% or more down there is no premium and your own amortization applies.
The engine passes 77 automated checks — the old payment re-derived independently and simulated to under a cent, every input adjustment asserted as a hand-computed literal, both paths pinned to direct engine calls and to a second, independently written method, collapse identities (no old home → both paths equal the plain qualifier), and monotonicity in rent and selling costs. The affordability engine underneath carries its own 1,060-check harness. Arithmetic last verified October 23, 2026. It’s an illustration, not a quote, tax advice, or a commitment to lend.
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