Income tax is a percentage of your earnings that goes to federal and state governments

Income tax is not a flat amount — it is a percentage of the money you earn from work, investments, or other sources. The percentage you pay depends on how much you earn, your filing status (single, married, head of household), and whether you live in a state that collects income tax. The federal government takes a cut, and most states take a separate cut. Some cities do too.

The amount you owe is calculated using tax brackets, which means you do not pay the same rate on every dollar. If you earn $50,000, you do not pay the top rate on all of it — you pay lower rates on the first portion, then higher rates as you climb into higher brackets. This is why two people earning different amounts pay different total taxes, and why earning more money does not always mean you take home proportionally less.

Key Takeaways

  • Federal income tax rates range from 10% to 37% depending on your income and filing status, but you pay different rates on different portions of your income.
  • State income tax varies by state — some states charge no income tax at all, while others charge up to 13%.
  • Your employer usually withholds tax from each paycheck, so you do not owe a lump sum on April 15 unless you owe more than what was withheld.
  • Self-employed people and those with investment income often owe taxes that were not withheld, and may need to make quarterly payments.
  • Filing a tax return tells the government how much you actually owed versus how much was already taken from your paychecks.

Federal tax brackets and rates for 2024

The federal government uses seven tax brackets. The rates are 10%, 12%, 22%, 24%, 32%, 35%, and 37%. The bracket you fall into depends on your total income and your filing status. A single person earning $47,000 is in a different bracket than a married couple earning $47,000 together.

Here is how brackets work in practice: if you are single and earn $50,000 in 2024, you do not pay 22% on all of it. You pay 10% on the first $11,600, then 12% on the next portion up to $47,150, then 22% on the remaining amount. Your total federal tax is roughly $5,700, not $11,000. The actual calculation depends on deductions and credits you may be may have access to to, which can lower your tax further.

These bracket ranges change each year because they are adjusted for inflation. The IRS publishes updated brackets in October or November for the following year, so the 2025 brackets will be slightly different from 2024.

State income tax varies widely or does not exist

Nine states have no state income tax at all: Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming, and New Hampshire (which taxes only investment income). If you live in one of these states, you owe only federal income tax on your wages.

States that do collect income tax charge between 1% and 13%, depending on the state and your income level. California, Hawaii, New York, Oregon, and Vermont have some of the highest rates. Some states use a flat tax (everyone pays the same percentage), while others use brackets like the federal system. Your state tax return is separate from your federal return, and you file it with your state's tax authority, not the IRS.

If you moved during the year or work in a state different from where you live, you may owe taxes to both states. Some states have reciprocal agreements that prevent double taxation, but you still have to file in both places to claim the credit.

How withholding works and why your paycheck is smaller than your salary

When you start a job, you fill out a W-4 form that tells your employer how much federal tax to take from each paycheck. You also fill out a state withholding form if your state has income tax. Your employer sends that withheld money to the IRS and your state on your behalf throughout the year.

The amount withheld depends on your W-4 answers: how many dependents you claim, whether you have a second job, and whether you have other income. If you claim too many dependents, too little is withheld and you owe money when you file. If you claim too few, too much is withheld and you get a refund. Neither is ideal — withholding too much means you gave the government an interest-free loan all year.

Self-employed people do not have an employer to withhold taxes, so they must pay estimated quarterly taxes four times a year (April, June, September, and January). If you do not pay enough in quarterly payments, you may owe a penalty when you file your annual return, even if you do not owe additional tax.

Deductions and credits that lower what you owe

Your total income is not the same as your taxable income. You can reduce taxable income by taking deductions. The standard deduction is a flat amount that most people subtract from their income — for 2024, it is $14,600 for single filers and $29,200 for married couples filing jointly. If you have significant expenses like mortgage interest, charitable donations, or medical bills, you might benefit from itemizing deductions instead, but most people use the standard deduction.

Tax credits are different from deductions — they directly reduce the tax you owe, dollar for dollar. The Earned Income Tax Credit (EITC) is a major credit for lower-income workers. The Child Tax Credit gives money back to parents. These credits can result in a refund even if you owe no tax.

What happens when you file your tax return

You file a tax return (usually Form 1040) to tell the IRS and your state exactly how much you earned and how much tax you owe. The return calculates the difference between what you actually owe and what was already withheld from your paychecks. If more was withheld than you owe, you get a refund. If less was withheld, you owe the difference.

You must file by April 15 of the following year (or the next business day if April 15 falls on a weekend). If you cannot file by then, you can request an extension, but that only extends the filing deadline — it does not extend the payment deadline. If you owe tax and do not pay by April 15, you will owe interest and penalties on top of the tax itself.

Most people file using tax software, a tax preparer, or a free service if their income is below a certain threshold. The IRS does not send you a bill — you calculate what you owe on your return and pay it, or claim your refund.

Self-employment tax and additional taxes on investment income

If you are self-employed, you owe self-employment tax in addition to income tax. This covers Social Security and Medicare taxes that an employer would normally pay on your behalf. Self-employment tax is 15.3% of your net self-employment income (12.4% for Social Security, 2.9% for Medicare). You can deduct half of this from your income tax, but you still owe the full amount.

Investment income — dividends, capital gains, interest — is also taxable. Long-term capital gains (assets held over one year) are taxed at lower rates than ordinary income: 0%, 15%, or 20% depending on your total income. Short-term gains are taxed as ordinary income. If your investment income is high enough, you may also owe an additional 3.8% net investment income tax.

Frequently Asked Questions

Why do I owe money at tax time if my employer was taking taxes out of my paycheck?

Your employer withholds based on your W-4, which is an estimate. If you have a second job, freelance income, investment income, or claimed too many dependents on your W-4, not enough was withheld. You file a return to settle the actual amount owed versus what was already taken.

Do I have to file a tax return if I did not earn much money?

If your income is below the standard deduction for your filing status, you generally do not have to file. However, if you had taxes withheld, you should file to get a refund. If you are self-employed, you must file if you earned $400 or more in net self-employment income, regardless of total income.

What is the difference between a tax deduction and a tax credit?

A deduction reduces your taxable income, so it saves you tax at your marginal rate. A credit directly reduces the tax you owe, dollar for dollar. A $1,000 credit saves you $1,000 in tax; a $1,000 deduction saves you tax only on that $1,000 (roughly $120 to $370 depending on your bracket).

Can I change my W-4 during the year if I realize I am withholding too much or too little?

Yes. You can submit a new W-4 to your employer at any time. If you are withholding too much, you can adjust it to take home more pay. If you are withholding too little, you can adjust it to avoid owing a large amount at tax time.

What happens if I do not pay my taxes by April 15?

You will owe interest on the unpaid amount, starting at 8% per year, plus a failure-to-pay penalty of 0.5% per month. If you cannot pay in full, you can set up a payment plan with the IRS. Filing your return on time, even if you cannot pay, reduces penalties.