Short Term Capital Gains Tax Calculator
Price the holding-period cliff — the single day that separates ordinary income rates from preferential ones, and what waiting for it is worth per day.
Short Term Capital Gains Tax Calculator
Results recalculate instantly on every keystroke. Nothing you type is transmitted.
What this result does not account for
- Results are a model, not a quotation — an institution's own figures govern.
- Every input is an assumption; change one and the answer changes with it.
- Rounding is applied only at the display layer, so totals may differ by a cent from a statement that rounds each line.
In short: A $60,000 gain alongside $95,000 of income costs $13,997.50 if held a year or less, against $9,000 if held one day longer. That single day is worth $4,997.50 — 8.33% of the gain and 35.70% less tax — or $166.58 for every day you are still short of the threshold.
Formula
The holding period is measured from the day after acquisition to the disposal date. One year and one day qualifies; exactly one year does not.
Worked Example
- Tax it as ordinary income. Adding $60,000 to $80,400 of taxable income costs $13,997.50.
- Tax it at long-term rates. The same gain stacked into the 15% band costs $9,000.
- Measure the cliff. $13,997.50 − $9,000 = $4,997.50 — 35.70% less tax.
- Divide by the wait. Thirty days short means waiting is worth $166.58 per day.
- Find the break-even. You could absorb a $4,997.50 price fall — 5.55% of a $90,000 position — and still be level.
Analyst's note. This is one of the few places in the tax code where a single day carries a genuinely large price, and the break-even framing is the one that should drive the decision. Waiting is only worthwhile if you expect the position to fall less than $4,997.50 — 5.55% of a $90,000 holding — over the remaining period. For a volatile asset thirty days out, that is a real risk and selling early can be entirely rational. For a stable one it is nearly free money. Note that the Net Investment Income Tax applies to short and long-term gains alike, so it never affects the cliff itself — only the absolute burden.
Strengths & Limits Of This Model
Where this engine is strong
- Runs entirely in your browser — no figure you type is transmitted or stored.
- Shows the full working, so every number can be traced and challenged.
- Free, unmetered and free of affiliate incentives.
Where it stops
- Generalised assumptions cannot capture every individual circumstance.
- Jurisdiction-specific rules and mid-year changes may not be reflected.
- A model output is not a substitute for a professional review of your position.
Practical Use Cases
Deciding whether to wait out a holding period
Compare the per-day value against the volatility of the position. At $166.58 a day the wait is worth protecting; if the asset could plausibly drop 5.55% in a month, selling now may be the better risk.
Timing a sale near the anniversary
The threshold is one year and one day, measured from the day after purchase. Selling on the anniversary itself still counts as short-term, which is a costly and very common error.
Choosing which lot to sell
Specific identification lets you sell long-held lots first and leave recent purchases untouched. Combine with the Capital Gains Tax Calculator to see the full burden on each option.
Methodology & Editorial Standards
Short-term gains are computed as the incremental ordinary income tax from adding the gain to taxable income under 2024 single-filer brackets, which correctly captures bracket crossing. The long-term comparison stacks the same gain across the preferential 0/15/20 bands. The holding period runs from the day after acquisition through the disposal date, so one year and one day is the qualifying threshold — an asset sold exactly one year after purchase remains short-term. The Net Investment Income Tax is shown separately because it applies identically to both treatments and therefore never changes the cliff. State tax is not modelled and in most states applies equally to both, likewise leaving the cliff unchanged. Wash sales, constructive sales, straddles and Section 1256 contracts with their 60/40 treatment are outside scope. Not tax advice. The engine implements the standard published formula for this calculation. Inputs are validated for domain and sign before evaluation, and any undefined case returns an em-dash rather than a spurious value.
Computation runs in IEEE-754 double precision at full internal precision; rounding to two decimal places occurs strictly at the display layer, so no cumulative drift enters the result. All monetary outputs use accounting presentation — grouped thousands, two decimals, negatives in parentheses — so figures can be transcribed directly into a model or working paper. Division-by-zero and out-of-domain inputs return an em-dash rather than a misleading number.
This engine was reconciled against an independent reference implementation and hand-verified for the worked example above before release. Our full five-stage review process is published on the About Us page.
Disclaimer. This calculator is provided for informational and modelling purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Verify all figures with a qualified professional before acting on them.
Short Term Capital Gains Tax Calculator — 20 Expert FAQs
20 analyst-written answers to the questions practitioners actually ask — optimised for voice and answer-engine retrieval.
How are short-term capital gains taxed?
As ordinary income at your marginal bracket. A $60,000 gain on top of $80,400 of taxable income costs $13,997.50 — an effective 23.33%, against 15% if held longer.
What is the holding period for long-term treatment?
More than one year, measured from the day after acquisition. One year and one day qualifies; selling exactly on the anniversary does not, which is a costly and surprisingly common mistake.
How much is one extra day worth?
$4,997.50 here — 35.70% less tax on the same gain. Spread across thirty remaining days that is $166.58 for every day you continue to hold.
Should I always wait for long-term treatment?
Only if the expected price fall is smaller than the tax saved. You could absorb a $4,997.50 decline — 5.55% of a $90,000 position — before waiting becomes the worse choice.
Does the NIIT apply to short-term gains?
Yes, at the same 3.8% as long-term gains once MAGI exceeds the threshold. Because it applies to both equally, it never changes the value of the holding-period cliff.
How is the holding period counted?
From the day after the trade date of purchase through the trade date of sale. Settlement dates do not govern, and the day of purchase itself is excluded from the count.
What if I bought in several tranches?
Each lot has its own holding period. Specific identification lets you choose which lot to sell — selling the oldest first usually maximises long-term treatment.
Are short-term losses more valuable?
Yes, marginally. They offset short-term gains first, which are taxed at higher ordinary rates, so a dollar of short-term loss shelters a more expensive dollar of gain.
Does this apply to crypto?
Yes. Digital assets are treated as property, so the same one-year threshold and rate structure apply. Frequent trading generates short-term gains almost exclusively.
What about day trading?
All gains are short-term and taxed as ordinary income, with no preferential rate available. Traders meeting the trader-in-securities standard face a different regime with its own elections.
Can I avoid short-term rates by transferring the asset?
No. Gifting transfers your basis and holding period to the recipient rather than resetting them, and a sale by them is taxed on the original acquisition date.
How do options affect the holding period?
Substantially. Writing a covered call against a position can suspend the holding period, and exercising an option starts a new one. This is a genuine trap for anyone combining strategies.
What if my income is low?
The cliff shrinks or disappears. If the gain would fall in the 0% long-term band and your ordinary rate is 10% or 12%, the gap narrows considerably — the engine computes it directly for your income.
Does a wash sale affect the holding period?
Yes. When a loss is disallowed, the holding period of the disallowed shares is added to the new position, which can help you reach long-term treatment sooner.
Should I sell before year end?
It depends on which year carries the lower other income, since short-term gains stack into your ordinary brackets. Deferring into a lower-income year can reduce the marginal rate applied.
Is this short term capital gains tax calculator free to use?
Yes. It is free, requires no account, and has no usage limits. ApexConverter is funded by contextual advertising, never by selling user data.
Is my data sent to a server?
No. The engine runs as Vanilla JavaScript inside your browser under our Zero-Server Client-Side Execution model. Your figures are computed locally and are never transmitted, logged, or stored.
How accurate is this calculator?
It applies the standard closed-form formula in IEEE-754 double precision, rounding only at the display layer. The engine is reconciled against an independent reference implementation before release.
Does it work on mobile?
Yes. The interface is mobile-first with numeric keypad hints and is tested down to a 320-pixel viewport with no horizontal scrolling.
Can I use it offline?
Largely, yes. Because computation is client-side, the page continues to calculate without a network connection once it has loaded.