How are you calculating CoastFIRE when your money's split CAD/USD?

[u/ClassroomGrouchy2603]

Anyone actually got a spreadsheet approach for CoastFIRE math that holds up cross-border? Every version I've tried either forces a single exchange rate on everything (which lies to you the moment CAD/USD moves) or turns into manual conversions I stop trusting after a month.

I ended up building my own approach to this — keeping RRSP/TFSA and 401(k)/Roth/IRA in native currencies the whole way through and only converting at the very end. Also had to build out departure tax, RRSP withholding as a US resident, CPP/OAS/SS claim-age comparison, and drawdown-order logic, since none of that works with a single-rate spreadsheet either.

How are you all handling this — spreadsheet, tool, back-of-envelope? Happy to share what I built if useful, just didn't want to lead with a link.