$500K by 40 and never save again? The CoastFIRE math for a Canadian couple
The claim: a couple with $500K invested at 40 can stop contributing and let compounding plus CPP and OAS carry them to 65. Here's what that actually buys — and the three assumptions it quietly leans on.
A thread this week put a number on the CoastFIRE idea: a couple with $500,000 invested by 40 can stop saving for retirement entirely, let compounding do 25 years of work, and lean on CPP and OAS to fill the rest. It got 200 comments because half the replies said "roughly right" and the other half said "you're missing something." Both halves were correct. The math works — for a specific couple, with a specific spending number, and a paid-off home. Change any of those and it stops working fast.
What $500K becomes by 65
Everything below is in today's dollars, so the return is a real, after-inflation number. A balanced portfolio has historically delivered somewhere between 3% and 5% real; we'll carry all three.
| Real return | $500K at 40 → 65 | 4% withdrawal |
|---|---|---|
| 3% | $1,047,000 | $41,900/yr |
| 4% | $1,333,000 | $53,300/yr |
| 5% | $1,693,000 | $67,700/yr |
At the middle case, the couple arrives at 65 with about $1.33 million and draws roughly $53,000 a year without ever adding another dollar. That is the "compounding does the rest" claim, and it holds.
What CPP and OAS add
This is where the thread's optimists were right: government benefits are bigger than most 40-year-olds assume. At the current quarter's rates, OAS pays $752/month per person at 65, and the CPP maximum is $1,508/month. Almost nobody gets the maximum — a typical earner lands closer to 60% of it.
- Two OAS cheques plus two 60%-of-max CPP pensions: about $39,800/yr.
- Two OAS plus two maximum CPP pensions: about $54,200/yr.
Add the 4%-real portfolio draw and the realistic couple has roughly $93,000 gross to work with from 65. Run that through the retirement income calculator for Ontario — each spouse with OAS, a 60% CPP, and a $26,600 RRIF draw — and the tax bill is small: about $5,000 per person, an effective rate near 11%, no OAS clawback in sight. Call it $83,000 a year after tax for the household.
For a couple with no mortgage and no kids at home, $83,000 net is a comfortable retirement. The brother in the thread was right.
The three assumptions doing the heavy lifting
1. The house is paid off. The whole calculation assumes shelter is nearly free from 65 on. A couple still carrying $2,000/month of mortgage or paying Toronto rent needs another $24,000 a year, which means a nest egg closer to $1.15 million on top of benefits — the coasting portfolio at 4% covers it, but at 3% it doesn't. Check what income your own spending target actually requires in the retirement calculator.
2. Both spouses have real CPP records. The $39,800 benefits figure assumes two 60%-of-max pensions. If one partner spent years out of the workforce, their CPP could be a few hundred dollars a month. Drop one CPP to 25% of max and the household benefits fall to about $33,500; the portfolio has to make up the gap forever.
3. The return is 4% real, every year, for 25 years. At 3% real the portfolio draw is $41,900 instead of $53,300 — an $11,000-a-year difference the couple can't fix at 63. Zero contributions means zero ability to course correct. A couple that keeps adding even $10,000 a year while "coasting" ends up around $1.75 million at 4%, which is the difference between the plan surviving a bad decade and not.
Retiring earlier breaks it
The thread's premise was retirement at 65. Pull that forward to 60 and two things happen at once: five fewer years of compounding (about $1.1 million at 4% instead of $1.33 million) and five years of zero CPP and OAS. The portfolio carries 100% of spending until 65. On an $80,000 budget that's $400,000 gone before a single benefit cheque arrives. Coasting to 65 and coasting to 60 are different plans by a wide margin.
How rare is $500K at 40, anyway?
Rare. The median Canadian household net worth at 40 — including home equity — is about $409,000. A couple with $500K in investments plus a home is comfortably in the top quarter of their age group. See where your own number lands in the net worth by age tool. CoastFIRE is a real option for that couple; for the median household the more useful question is what a continued contribution does, and the retirement calculator answers it.
The takeaway
Yes: $500K invested at 40, a paid-off home, two decent CPP records, and a 4% real return produce roughly $83,000 after tax for a couple from 65 — with no further saving. Change any one of those four inputs and the answer moves by five figures a year. The plan isn't wrong; it just has no margin. Run your own spending number through the retirement calculator and see how much cushion you actually have before you stop contributing.
Retirement and benefit figures delivered by Metrestick. OAS, CPP, and GIS amounts: Employment and Social Development Canada, July–September 2026 quarter (Open Government Licence – Canada). Net worth by age: Statistics Canada, Survey of Financial Security, 2023. Growth figures are illustrative and not advice.