You are looking at a down position and a calendar.

This estimator answers one question: if you sold that lot today, how much of the loss could offset gains and other income on a 2025 federal return, and how much would carry forward.

An unrealized loss changes nothing on a return; only a real taxable sale does.

Estimate - not tax advice. Before you sell, check the dated wash-sale rule.

Use the tax-loss harvesting estimator

The form asks for the tax year, filing status, taxable income or the marginal rates to apply, and one row per candidate lot: asset, units, acquisition date, adjusted basis, estimated proceeds and selling costs.

Then add this year's realized short-term and long-term results and any prior-year carryovers of each class.

The direct-crypto versus security-wrapper control is required. A blank field is flagged, not read as zero, because a missing acquisition fee or carryover moves the answer.

What this tool does

It estimates a potential realized loss per lot, runs the netting order, applies the ordinary-income cap, and shows the carryforward and an approximate saving at your selected rate. Unsure which lots to sell? Start with the record questions: browse the crypto tax calculators.

How the result is calculated

For each lot, potential loss is max(0, adjusted basis minus estimated net sale proceeds), made real only by an actual taxable sale. One year or less is short-term; more than one year is long-term.

The estimator nets within each class, applies any excess against the opposite class, then applies the rest against ordinary income: at most $3,000 ($1,500 if married filing separately), with unused loss carried forward on the Schedule D carryover worksheet.

Every intermediate figure is displayed.

The final rate multiplication is an approximation, not how a return computes tax. Source for the netting and limit: the IRS 2025 Instructions for Schedule D. Verified rules here are 2025; anything labeled 2026 is a provisional projection.

Worked example

Two invented lots. Watch the cap bite before the long-term loss does much work.

Illustrative test file - invented amounts, not a real ledger

Lot Acquired Adjusted basis Estimated net proceeds Class Potential loss
TEST-A, 1.5 units 2025-04-02 $9,400 $5,900 Short-term $3,500
TEST-B, 8 units 2022-11-18 $14,200 $6,700 Long-term $7,500

Already realized this year: short-term gain $2,000; long-term gain $1,000. No prior-year carryovers.

  1. Short-term class: $2,000 gain less $3,500 loss = net short-term loss $1,500.
  2. Long-term class: $1,000 gain less $7,500 loss = net long-term loss $6,500.
  3. Cross-class: both classes are losses, so nothing offsets. Combined net capital loss $8,000.
  4. Ordinary-income offset: capped at $3,000 (or $1,500 if married filing separately).
  5. Carryforward: $5,000, keeping its short- and long-term character on the carryover worksheet.

Approximate saving on the $3,000 ordinary-income offset, assuming a 24% marginal rate: about $720. Separately, steps 1 and 2 used the losses to cancel the $3,000 of gains already realized this year, so those gains are not taxed.

Read your result

Recommended harvest amount is the total potential loss across the lots you flagged. Realized offset is the part absorbed by gains. Ordinary-income offset is the capped slice that reduces other income this year. Carryforward is the remainder, carried forward indefinitely. Estimated dollar saving is the offset times your selected rate: a rate approximation, not a refund prediction, so your input assumptions print beside it.

The 2026 warning sits next to every result, including zero. A zero can mean lots above basis, or a blank field. Check which.

Rates, rules and source dates

The 2025 figures are supported by the published IRS instructions (current figure at the IRS).

Tax year Filing status Ordinary-income loss cap Marginal-rate source Direct-crypto / security-wrapper wash-sale scope Source Verified at
2025 Single, MFJ, HoH, QSS $3,000 Rev. Proc. 2024-40 §§2.01 and 2.03 IRC §1091 covers stock or securities; the 2025 instructions do not automatically apply it to ordinary directly held crypto Instructions for Schedule D 2026-09-26
2025 Married filing separately $1,500 Rev. Proc. 2024-40 §§2.01 and 2.03 As above Instructions for Schedule D 2026-09-26
2026 (provisional) All Check that year's instructions Rev. Proc. 2025-32 Dated status only; check current law and legislation before a 2026 trade or filing Instructions for Schedule D 2026-09-26

Full brackets are not reproduced here; see how a loss reaches the return and the rate guide linked from it.

Edge cases and limits

Excess loss carries forward indefinitely, keeping its class, so a $40,000 loss in a year with $2,000 of gains is not a $40,000 deduction. A long-term loss offsets a short-term gain only after same-class netting, which decides whether harvesting a long-term lot helps this year.

A spot Bitcoin ETF share is a security, so its wash-sale analysis differs from that for coins in your own wallet.

A common rule disallows a loss after a substantially identical reacquisition inside a short window, but its asset-class application is jurisdiction-specific; work from the dated US distinction above, not an assumed automatic disallowance.

Buying back sets a new basis and holding-period clock, so a same-day round trip can turn a long-term position short-term. We do not treat an immediate repurchase as risk-free: legislation may change, and an economically empty round trip can attract an anti-abuse challenge.

Before you treat the estimate as decision-grade, confirm:

  • Ownership type: coins held directly, or shares in a fund
  • Acquisition date and adjusted basis, with the acquisition fee actually included
  • Sale proceeds and selling costs, from an executed trade rather than a screen price
  • Gains and losses already realized this year, both classes
  • Prior-year short-term and long-term carryover amounts
  • The source date on the rule you are relying on
  • An economic reason for the sale beyond the deduction

An unchecked box should show as a flagged blank, not a zero. In one dated test file, a $180 acquisition fee left out of basis shrank the loss by $180 and pulled the harvest below the tester's threshold for selling.

For the legal detail, check the dated wash-sale rule.

What this tool cannot tell you

It cannot confirm your lot records: whether your basis includes every fee, a transfer kept its history, or two lots are really one. It does not know the law after its verification date of September 26, 2026, or how a related or wrapped token is treated. It has no state tax logic and does not compute your return or final tax position.

Where the amount matters or a classification is arguable, take it to a CPA or an enrolled agent.

Common questions

Does a Bitcoin ETF loss work the same way as a loss on coins I hold directly? No. Fund shares are securities, so the separate wash-sale warning and its source date apply.

How much of my crypto loss can reduce my other income this year? After capital-gain netting, at most $3,000 for the 2025 tax year, or $1,500 married filing separately. The rest carries forward indefinitely, keeping its character.

If I sell and buy back the coin, what happens to the new lot? It gets a new basis equal to what you paid and a restarted holding-period clock. For the loss itself, check the dated wash-sale rule as of your trade date.

Why does the estimated saving differ from what my return shows? The widget multiplies an offset by one selected rate; a return applies brackets, credits, phase-outs and state rules to your actual figures. Treat the output as a federal approximation.

To choose lots, compare your purchase lots; to price a later sale of a repurchased position, estimate the tax on a later sale.

Guides: check the dated wash-sale rule and see how a loss reaches the return. Hub: browse the crypto tax calculators.

Check each lot against your records and the source date before using this estimate to plan a sale.

Sources

Estimate - not tax advice. To see where a harvested loss lands, follow the Form 8949 walkthrough.