Capital Gains Tax Loss Harvesting
Federal • 2024/2025 • ST/LT netting + harvesting

Capital Gains & Tax‑Loss Harvesting

Estimate federal capital gains tax (stocks/crypto) and how much loss to harvest to offset gains.

Inputs

Simplified estimator; does not enforce wash sale rules.

Deductions + gains/losses

Estimated summary

Net short‑term
$5,000
Net long‑term
$12,000
LTCG 0%: $0 • 15%: $12,000 • 20%: $0
Federal tax (ordinary + LTCG)
$14,314
Ordinary tax: $12,514 • LTCG tax: $1,800
Losses to harvest (to offset gains to ~$0)
$17,000
Simplified target based on net gains. Actual tax impact depends on ST vs LT mix and your brackets.

Safety note

This is an estimator. Wash sale rules and investment‑specific reporting can materially change your allowed losses.

Notes & tables

Tax tables (2025 vs 2026): quick reference


Standard deduction

Filing status
2025
2026
Single
$15,000
$16,100
Married Filing Jointly
$30,000
$32,200
Head of Household
$22,500
$24,150
Married Filing Separately
$15,000
$16,100

Ordinary income brackets (Single / MFJ / HOH)

Year
10% top
12% top
22% top
24% top
32% top
35% top
37% starts
2025 — Single
$11,925
$48,475
$103,350
$197,300
$250,525
$626,350
$626,351+
2026 — Single
$12,400
$50,400
$105,700
$201,775
$256,225
$640,600
$640,601+
2025 — MFJ
$23,850
$96,950
$206,700
$394,600
$501,050
$751,600
$751,601+
2026 — MFJ
$24,800
$100,800
$211,400
$403,550
$512,450
$768,700
$768,701+
2025 — HOH
$17,000
$64,850
$103,350
$197,300
$250,500
$626,350
$626,351+
2026 — HOH
$17,700
$67,450
$105,700
$201,775
$256,200
$640,600
$640,601+

Short‑term vs long‑term (why it matters)


Short‑term (ST): assets held **≤ 1 year** → taxed like ordinary income.
Long‑term (LT): assets held **> 1 year** → taxed at 0% / 15% / 20% (depending on your taxable income).

This calculator estimates both and applies simplified netting rules (ST vs LT gains/losses).


Netting rules (plain English)


1) Net ST gains – ST losses → net ST

2) Net LT gains – LT losses → net LT

3) If one is positive and the other negative, they offset each other

4) If you end with net loss overall, up to $3,000 can reduce ordinary income, then carry over the rest


Tax‑loss harvesting (the goal)


Tax‑loss harvesting means realizing losses to reduce taxes:


Offset capital gains (ST offsets ST, LT offsets LT; then cross‑netting)
If you end up with net loss, you can deduct up to $3,000 against ordinary income (then carry over the rest)

Harvesting checklist (content that drives searches)


Confirm which positions are at a loss (unrealized)
Estimate your net gains after netting (this calculator)
Decide whether you want to offset gains to $0 or to a target
Avoid accidental wash sales if you want the loss to count
Save records (cost basis, lots, 1099 forms)

Table: common year‑end questions


Question people search
Practical answer
“How much loss do I need to realize to offset my gains to zero?”
Roughly your net gains amount (after netting)
“Do short‑term gains hurt more?”
Usually yes — taxed at ordinary rates
“Why does LT gain sometimes show 0% tax?”
Because you’re within the 0% LT bracket after stacking
“Can I deduct a big loss?”
Up to $3k vs ordinary income + carryover

Related calculators (internal linking)


Choosing deductions? [Standard vs Itemized](/us/taxes/standard-vs-itemized-deductions)
Checking refund impact? [Tax Refund Estimator](/us/taxes/tax-refund-estimator)

Related tools

[Tax Refund Estimator](/us/taxes/tax-refund-estimator)
[Standard vs Itemized](/us/taxes/standard-vs-itemized-deductions)

FAQ (10)

Do I pay capital gains tax on crypto in the US?

Yes, in most cases. The IRS treats crypto as property. Selling or swapping typically realizes a capital gain or loss, taxed short‑term or long‑term depending on holding period.

What’s the difference between short‑term and long‑term gains?

Short‑term gains are from assets held 1 year or less and are taxed like ordinary income. Long‑term gains are held more than 1 year and may qualify for lower 0%/15%/20% rates.

How does netting gains and losses work?

You net short‑term gains against short‑term losses and long‑term gains against long‑term losses. If one side is negative and the other positive, they can offset each other to reach a single net capital gain or loss.

How much loss should I harvest to offset gains?

A simple target is to harvest losses equal to your net gains (after netting). The exact tax impact also depends on whether those gains are short‑term or long‑term and your income bracket.

Can capital losses reduce my ordinary income?

If you end up with a net capital loss, you can usually deduct up to $3,000 against ordinary income in the current year, with the rest carried forward.

What is a wash sale?

A wash sale rule can disallow a loss if you sell a security at a loss and buy the same or substantially identical security within the wash sale window. This calculator doesn’t enforce wash sale rules—treat it as planning only.

Why does my long‑term gain tax show 0%?

Because long‑term gains stack on top of ordinary taxable income. If total taxable income stays within the 0% LT bracket for your filing status, part of LT gains can be taxed at 0%.

Do long‑term losses help if I only have short‑term gains?

Yes. After netting within each category, opposite‑sign ST/LT amounts can offset each other. A net long‑term loss can reduce net short‑term gain (and vice versa).

Is capital gains tax based on AGI or taxable income?

Rates for long‑term capital gains depend on taxable income and stacking rules (ordinary income fills the brackets first). This estimator models that simplified stacking approach.

Can I use this for 2024 and 2025?

Yes. Select the tax year and filing status. The calculator uses year‑specific long‑term capital gains brackets (0%/15%/20%).

Do capital gains affect my tax refund?

Yes. Gains can increase your tax liability. Whether that reduces your refund (or increases what you owe) depends on how much tax was withheld or prepaid during the year.

What if I only want to offset short‑term gains?

Short‑term gains are often taxed at higher ordinary rates, so many people prioritize harvesting losses that offset short‑term gains first. Netting rules can still mix ST and LT after initial netting.

Does this include state capital gains tax?

No. This page estimates federal outcomes. State treatment varies widely (some states tax gains as ordinary income).

Why does my broker’s 1099 not match my estimate?

Brokers use specific lot selection and report realized gains/losses. Your estimate can differ if you use different cost-basis assumptions (FIFO vs specific lots) or if wash sales apply.