Your year so far
Positions you could sell at a loss
Enter each loss as a positive number. Leave unused rows blank.
Fill in your gains and at least one position, then click Estimate savings.
Result
Before and after harvesting
| No harvest | With harvest |
|---|
How it is calculated
Short-term gains less short-term losses, and long-term gains less long-term losses, give two nets. If one is a gain and the other a loss they offset each other. A remaining net loss reduces ordinary income by up to $3,000 ($1,500 if married filing separately), using short-term losses first, and the rest carries forward. Tax is the taxable short-term amount at your ordinary rate plus the taxable long-term amount at your long-term rate, each plus your state rate and any net investment income tax you enter; the deduction is worth ordinary plus state rate. Savings is tax with no harvest minus tax with the eligible losses. Positions marked as bought back within 30 days are excluded as possible wash sales.
Not modelled: tax brackets that shift as income changes, the actual net investment income tax threshold, state rules that differ from federal, the 61-day wash-sale window across accounts and spouses, wash sales triggered by dividend reinvestment, crypto and other special rules, alternative minimum tax. Unverified: checked by hand calculation and unit tests only.
Common questions
How does tax-loss harvesting work?
You sell investments that are worth less than you paid, which realizes a capital loss. That loss first cancels capital gains you realized in the same year, short-term against short-term and long-term against long-term, then the two totals offset each other. If losses are still left, up to $3,000 a year ($1,500 if married filing separately) reduces ordinary income and the rest carries forward.
How much can tax-loss harvesting save me?
The saving is the tax you would have paid on the gains the losses cancel, plus the ordinary-income deduction times your bracket. Short-term gains are taxed at ordinary rates, so cancelling them saves the most. This tool prices it with the flat rates you enter.
What is the wash-sale rule?
If you buy the same or a substantially identical security within 30 days before or after selling it at a loss, the loss is disallowed for now and added to the basis of the new shares. Mark a position as wash-sale risk and this tool leaves its loss out.
Does harvesting erase the tax?
No, it defers it. Your lower basis means a bigger gain when you eventually sell the replacement. It pays off if you hold long enough, get a step-up in basis, donate the shares, or sell in a lower bracket, and the tool shows the deferred amount.
What happens to losses I cannot use this year?
They carry forward indefinitely and keep their short-term or long-term character. Enter last year's carryforward in the form so it is netted first.
Are short-term or long-term losses better to harvest?
A short-term loss first cancels short-term gains, which are taxed at higher ordinary rates, so it is usually worth more when you have those. Compare both in the tool by changing each position's term.
Does this include state tax and the net investment income tax?
Only as flat percentages you type in. The state rate is added to every rate and the 3.8 percent net investment income tax, if you enter it, is added to gains. Real state rules and thresholds vary.
Is my information uploaded anywhere?
No. Everything you type stays in this browser tab. There are no accounts, cookies or analytics vendors.