Run the same 100,000 (dollars, pounds, whatever the local currency is) through four different countries' tax systems and you get four genuinely different answers about what that number actually means for your bank account. Here's what actually happens to it, worked out properly rather than left as a vague "it depends."
A worked comparison at 100,000 gross
Using each country's current national-level rules only — before any state, provincial, or regional tax is layered on top:
| Country | National tax + payroll deductions | Take-home |
|---|---|---|
| US (federal + FICA, no state) | $20,820 | $79,180 |
| UK (Income Tax + NI) | £31,443 | £68,557 |
| Canada (federal only) | $13,323 | $86,677 |
| Australia (Income Tax + Medicare Levy) | $22,520 | $77,480 |
The UK number looks brutal next to Canada's federal-only figure, but that's only half the picture — Canada's federal calculation above doesn't include provincial tax, which is never optional. Add Ontario or Quebec's own brackets on top and the real gap narrows considerably. This is exactly the trap: comparing one country's full tax bill to another country's partial one makes for a dramatically misleading headline.
Why "federal only" isn't the real number for three of these four
The US stacks federal tax, FICA (7.65% straight off the top for most employees), and — in 42 states — a state income tax layer that can range from nothing to double digits. Canada does the same thing with federal-plus-provincial: Alberta's flat 10% provincial rate lands very differently than Ontario or Quebec's progressive brackets, even on identical federal-taxable income. The UK is the outlier here — Income Tax and National Insurance are both calculated nationally, with Scotland the only real regional exception. Australia sits in between: national income tax plus a 2% Medicare Levy, with no separate large payroll tax deducted from the paycheck the way US FICA works, though the employer-paid Superannuation Guarantee (not deducted from salary at all) is part of the broader compensation story.
The mistake people actually make
Comparing a $100,000 offer in Toronto against a £100,000 offer in Manchester by gross salary alone tells you almost nothing useful. The real comparison needs the full local tax stack — national plus regional — run against the actual cost of living in each specific city, not just the tax code. Gross salary is the headline. Take-home pay, against local prices, is the actual answer.
Run your own specific numbers rather than a generic example: US Income Tax, UK Take-Home Pay, Canada Income Tax, or Australia Income Tax.
A few things people actually ask
Which country taxes 100,000 the hardest?
By national-level rules alone, the UK's combined Income Tax and National Insurance take the largest bite in this comparison — but that's not the whole story once state, provincial, or regional tax gets added to the others.
Why isn't Canada's federal tax the full picture?
Because provincial tax is never optional — it's added on top of the federal calculation everywhere in Canada, and can vary significantly depending on the province, from Alberta's flat rate to Ontario or Quebec's progressive brackets.
Is comparing gross salaries across countries useful at all?
Only as a very rough starting point. The number that actually matters is take-home pay weighed against local cost of living — two very different things a bare gross salary comparison completely ignores.