http://www.pbs.org/newshour/rundown/health-costs-how-the-us-...
Nb income based taxes are only the start anyway property tax aka Council tax is quite a burden on lower income households in the UK.
The median salary in the UK in 2015 was roughly 27,500 GBP.
Let's do the numbers as percent of wages first. This won't match perfectly with the OECD numbers as I haven't matched up the personal allowance rates etc. by tax year.
But currently, 27,500 means your taxable income is 16,500 (after subtracting the personal allowance). On this you'd pay 20% income tax, or 3,300 and 8.5% employee national insurance for roughly 2,332. Your total tax would be 28.5% of your taxable income, but only 20.5% of income once you factor your personal allowance back in.
If w're looking at employer contributions, I don't know exactly what they stand at this moment, but it used to be 12.5% of gross salary. If we adjust the numbers above, that means 3437.5 in employer contributions for a total tax wedge of ~29.3%. Note that I have not taken into account the lower earnings threshold etc. for employer national insurance contributions, which I believe you should, so I think the total would actually be lower, but even so even when applying it to the full amount you actually still end up below the OECD figure.
Both of the above excludes council tax. Council tax is of course tricky because it depends on the property you live in and your council, and whether or not you live in the property alone.
Now in my property that adds 1600/year for a family. Though you wouldn't live here if you were a single earner family on an 27.5k salary, that'd drive the total tax wedge up to 34.5%. As a single, you'd get half off, and end up with a total tax wedge of 31.9%. Looking at the gross wage percentages, it'd bring taxes to 26.3% (couple) or 23.4% (single) respectively.
Belgium is the extreme - at 55.3% it's the highest in the OECD. Three European countries (UK, Ireland, Switzerland) come in below the US on this metric.
The numbers are basically all over the place, and depends more on overall culture and priorities than things like healthcare etc. by themselves.
In terms of what is directly visible to the employee, US is at 25.6% of gross wages (note the difference - these numbers can not be directly compared to the ones above, as the ones above are percentages of total labour cost including the employer contributions) compared to 23.4% for the UK, 36.1% for Denmark (Denmark is one of very few countries that don't "hide" hardly any of labour costs as part of employer social security contributions), or 28.4% for Norway, 24.7% for Sweden or 42% for Belgium. So still all over the place.
It also depends greatly on how much you earn, and how progressive your specific country's tax system is.
The only thing that's clear is that the US does not stand out as being nearly as much of a low tax country as people sometimes like to think. E.g. the OECD average (which to be fair is pulled down by several non-European countries) of employee contributions is 25.5%, so slightly below the US.
[1] http://www.keepeek.com/Digital-Asset-Management/oecd/taxatio...
[2] http://www.keepeek.com/Digital-Asset-Management/oecd/taxatio...