Taxes are calculated per year, it’s a progressive system, and you actually decide how much gets taken out of your paycheck.

For the taxes taken out of your paycheck, basically the software takes the allowances you put on your w4, and it then extrapolates out your entire year of income and takes out what you tell it to. So, it’s not actually a per paycheck thing, it’s a per year thing. It says, ok OP said that they get 2 allowances, and OP will make $xxxxx this year, so I need to withhold $yyyyy taxes for them.

This is why everyone (wrongly) thinks that bonuses and/or overtime are taxed higher- they aren’t, they are WITHHELD at a higher rate because the tax software assumed your yearly earnings would be $xxxxx and now you have this extra income it didn’t account for, so it takes out extra taxes so you don’t get screwed over at tax time.

The progressive nature of the tax code means that you aren’t taxed a flat x% on your income- google the tax tables and you can see what it looks like. Basically there are different buckets of income, and they are taxed at different rates. You have to fill up one bucket to move onto the next bucket.

Also remember that come tax time it’ll even out- if you overpaid over the year, and told your job to take out too much for taxes, you’ll get it back as a refund. On the flip side, if you withhold too little, you’ll owe come tax time.

Helpful tool: https://www.paycheckcity.com/calculator/hourly/