In the UK on an £80k ($108k) salary an employer would have to pay 89,820.08 ($120222), plus pension contributions and the employee would receive £55,092.76 ($73740)
In California someone paid $120k Gross I think would receive $79548, before healthcare deductions (optional private healthcare in the UK is typically about $700 a year for a single person of working age, in the US I believe premiums (employer and employee) are more like $7000 a year)
Overall at the $120k range it seems a similar cost in the UK vs California. Office space in London is probably higher than in SF, but that doesn't apply for remote workers.
> Do you mean expensive in terms of taxes, the market commending a higher salary, or other reasons?
The market. The US market for high-salaried knowledge work always pays more, whether is Tech, Finance, Legal etc.
In general, if you're a high-earner/rich, America is a great place to be. If you're poor, the UK offers more support and protections, but this is a digression.
Company private health plans in the UK don't cost anything like those in the US, though: They don't need top cover everything because the NHS will pick up things they don't.
Given the same salaries in both countries, it's probably more expensive to hire that employee in the US given that the US firm is expected to pay for fairly expensive health insurance.
UK firms pay for private health insurance too, but that's supplemental insurance on top of NHS coverage.
