California capital gains tax calculator
California capital gains tax calculator: enter what you paid and what you sold for, and the calculator below works out two bills, not one. The federal return taxes the gain on the 0/15/20 long-term schedule. California taxes the same gain as ordinary income on its own brackets, whatever the holding period.
The state layer is not a rounding error. On a mid-range long-term gain the California piece runs close to two thirds of the federal piece, because the state's schedule climbs to 12.3% while the federal schedule charges 15% to most filers. The page shows each layer, then the two added together.
How it works
How California taxes a capital gain
The federal layer reads the holding period first. Hold the asset more than one year and the long-term gain is taxed at 0, 15 or 20% percent, stacked above your other taxable income. For 2025 a single filer's 0 percent band reaches $48,350 of taxable income and the 15 percent band reaches $533,400. Sell at one year or less and the gain is short-term instead, inside the ordinary brackets that run to 37%.
California reads only the amount. The whole gain, long-term or short-term, joins your other income on the Form 540 return and walks the state's brackets from 1% up to 12.3%. For a single filer the 9.3% band spans $72,724 to $371,479 of taxable income. The state keeps its own standard deduction, $5,706 for 2025, a fraction of the federal figure.
Holding an asset longer changes the federal rate on its gain and leaves the California rate exactly where it was. That asymmetry is the whole reason a two-layer calculator beats a single-rate guess.
Worked example
Index fund held two years: $24,300 on a $100,000 gain
You buy $60,000 of an index fund in April 2023 and sell it for $160,000 in August 2025. Held well past one year, the $100,000 gain is long-term. Wages for the year are $95,000, filing single.
Federal first. Taxable income before the gain is $79,250 after the standard deduction, already above the $48,350 zero breakpoint, so the entire gain sits in the 15 percent band: $15,000. Modified adjusted gross income reaches $195,000, under the $200,000 net investment income tax threshold, so the 3.8 percent surcharge stays at zero.
California adds the same $100,000 to your wages. Both ends of the gain fall inside the 9.3% band, so the state charges $9,300 on it. Combined: $24,300 of tax on a $100,000 gain, an effective 24.3% before any state credits the calculator does not model.
One long-term share sale, 2025, single filer
| Step | Amount |
|---|---|
| Sale proceeds | $160,000 |
| Cost basis (purchase price) | $60,000 |
| Long-term capital gain | $100,000 |
| Federal tax on the gain at 15% | $15,000 |
| California tax on the gain at 9.3% | $9,300 |
| Combined tax on the gain | $24,300 |
The California details
What the state layer adds, and what it leaves out
- No long-term rate. The Form 540 booklet says it plainly: California taxes long and short term capital gains as regular income, and no special long-term rate exists. A stock held a decade and a stock held a week pay the same state rate on the same size of gain.
- A small deduction. The state standard deduction is $5,706 for a single or married-filing-separately return in 2025 and $11,412 for joint and head-of-household returns. Against a six-figure gain it barely registers.
- An extra 1 percent at the very top. Taxable income above $1,000,000 carries an additional 1 percent, the Behavioral Health Services Tax, formerly the Mental Health Services Tax. The calculator does not add it.
- Three schedules. Single and married-filing-separately returns use Schedule X, joint returns Schedule Y, head-of-household returns Schedule Z, and the calculator picks the schedule and the deduction from the filing status you choose. Itemised deductions and exemption credits are not modelled.
Questions
Frequently asked questions
Does California tax capital gains differently from wages?
No. A capital gain is ordinary income on the Form 540 return and walks the same brackets as salary, from 1 percent up to 12.3 percent. The preferential federal long-term rates do not flow through to the state.
What is California's capital gains tax rate?
There is no single rate. The gain is taxed across the state's brackets, so a small gain can start at 1 percent and a large one finishes at 12.3 percent. In this page's worked example the whole gain sat in the 9.3% band.
Do I still pay federal capital gains tax on a California sale?
Yes. The two layers are independent. The federal return applies the 0/15/20 schedule to a long-term gain, or ordinary rates to a short-term one, and California applies its own brackets to the same dollars.
Does holding the asset longer reduce the California tax?
No. The holding period changes only the federal rate. California charges the same rate on a gain whether you held the asset a month or a decade.
How does the standard deduction affect the gain?
The federal layer subtracts the federal standard deduction from your wages first; taxable income below the 0 percent breakpoint shelters part of a long-term gain at lower incomes. California subtracts only its own $5,706.
What happens in a year with losses?
Capital losses net against capital gains before either layer is computed. A net loss year reports no tax on gains, up to 3,000 dollars of the loss deducts against ordinary income federally, and the rest carries forward for the calculator to use next year.
Sources
Where these figures come from
Also on capitalgainstax.net