The profit shown by this calculator is a pre-tax estimate. What you actually keep depends on how the IRS treats the sale. This guide explains the main ideas in plain language, with an illustration, and points to the IRS sources. It is general education for U.S. readers, not tax advice, and tax rules change, so confirm current figures with the IRS or a qualified tax professional before you act.
For federal tax, the character of your gain depends on why you held the property. Under the Internal Revenue Code, section 1221(a)(1), property held primarily for sale to customers in the ordinary course of a trade or business is not a capital asset. People who buy houses mainly to renovate and resell them quickly, and who do this repeatedly, are often described as dealers; their profit is generally treated as ordinary business income. Someone who buys a property to hold as an investment and sells it later is more likely to be treated as an investor, whose profit can be a capital gain. There is no single bright-line test. The IRS and the courts look at facts and circumstances, such as how often you sell, how long you hold, how much you improve and market the property, and what your purpose was at purchase. Where you fall is a question for a tax professional.
If your sale is treated as a capital gain, the holding period matters. The IRS explains in Topic No. 409 that if you hold an asset for more than one year before you dispose of it, the gain or loss is long-term; if you hold it one year or less, it is short-term. Net short-term capital gains are taxed as ordinary income at graduated rates. For long-term gains, most net capital gain is taxed at 0, 15 or 20 percent depending on taxable income and filing status (IRS Topic No. 409, for tax years beginning in 2025). Most flips are completed in less than a year, so the short-term treatment, or ordinary business income treatment, is common in practice.
If your flipping counts as a business, you may also owe self-employment tax. The IRS (Topic No. 554) describes the rate as 12.4 percent for Social Security plus 2.9 percent for Medicare, 15.3 percent combined, applied to 92.35 percent of net earnings from self-employment; you generally must pay if net earnings are $400 or more. The Social Security part applies only up to a maximum amount of earnings that changes each year, so check the current limit at irs.gov.
Take the calculator's default deal, which shows a pre-tax profit of $58,700. For illustration only, suppose the IRS treated the sale as a business and you had no other earnings that year, and that the profit is below the Social Security limit. The self-employment tax estimate would be:
| Net profit (calculator result) | $58,700 |
| x 92.35 percent | $54,209 |
| x 15.3 percent = self-employment tax | about $8,294 |
That is before federal income tax, any state or local tax, and any deductions or credits. It shows why a flip that looks like a $58,700 profit can leave you with considerably less. If the same sale were an investor sale with a holding period of more than one year, the self-employment tax would not apply in the same way and the long-term capital gain rates would be the relevant ones, but that outcome depends on facts that the calculator cannot know. Tax calculations also use tax-basis figures, such as the amount realized and adjusted basis, which are not identical to a simple profit estimate.
Different rules apply if the house was your main home. The IRS (Topic No. 701) explains that you may be able to exclude up to $250,000 of gain ($500,000 if you file jointly) if you owned and used the home as your main residence for at least two of the five years before the sale. This is not available for a property you only renovate and sell without living in it, and a repeated pattern of short stays can attract questions. If you are thinking about it, talk to a professional first.
A short meeting before you buy can save a great deal of trouble. Consider asking:
None of this changes the arithmetic in the calculator. It changes what part of the profit you keep, which is why we show the profit as a pre-tax figure.
IRS Topic No. 409, Capital gains and losses; IRS Topic No. 554, Self-employment tax; IRS Topic No. 701, Sale of your home; Internal Revenue Code section 1221(a)(1). All at irs.gov or law.cornell.edu. Rates, thresholds and rules change, so always check the current year.
Run your own numbers in the calculator, read The 70% Rule Explained, or see the methodology. Guides: estimating ARV and repairs, how flip profits are taxed, holding costs and timeline.