Does this calculator distinguish between short‑term and long‑term capital gains?

No. It uses a single effective rate you provide. To approximate short‑term or long‑term treatment, choose a rate that reflects how the sale will likely be taxed, or run separate scenarios with different rates.

Can I include state tax, NIIT, or other surtaxes in the estimate?

Yes. Combine your expected federal, state, and surtax percentages into one effective rate and enter that figure. The calculator will then approximate your total tax on the gain using that rate.

Does this handle multiple tax lots or specific identification of lots?

No. It assumes a single purchase price and current price for the shares you enter. For portfolios with many lots and different holding periods, you may want to approximate using a weighted average or run separate calculations for each lot.

How should I think about tax‑loss harvesting with this tool?

This calculator focuses on realized gains from a sale. To see the net effect of pairing gains and losses, you can conceptually offset gains with realized losses when choosing how many shares to harvest or adjust your effective rate to reflect reduced taxable gains.

Is this capital gains harvest calculator tax or investment advice?

No. It is an educational estimate only and does not capture all tax rules, interactions, or personal circumstances. Use it as a starting point for planning, then confirm any harvest strategy with a qualified tax professional or financial advisor.

finance calculator

Capital Gains Harvest Calculator

Estimate gain, tax, and net proceeds from harvesting capital gains at your tax rate.

Results

Gain per share: $5,000
Total gain: $500,000
Estimated tax: $75,000
Net proceeds after tax: $2,425,000

Overview

Capital gains harvesting is the process of intentionally selling appreciated investments to realize gains—either to lock in profits, fill up a low tax bracket, or reset your cost basis. This capital gains harvest calculator helps you see the basic math: how much gain you would realize, how much tax you might owe at your chosen effective rate, and how much cash you would have left after tax if you sell at today’s price.

How to use this calculator

Enter your original purchase price per share and the current market price per share for the investment you are considering selling.
Enter the number of shares you plan to harvest (sell) in this transaction.
Enter an effective capital gains tax rate that reflects how this sale would likely be taxed (for example, a blended long‑term capital gains rate plus state tax and any applicable surtaxes).
Run the calculation to see gain per share, total gain, estimated tax owed on that gain, and your net after‑tax proceeds.
Experiment with different current prices, share counts, or tax rates to see how market moves and tax assumptions change your harvest outcome.

Inputs explained

Purchase price per share: Your original cost basis per share for this position, excluding commissions in this simplified view. For multiple lots, you can use an average cost or the cost basis of the specific lot you plan to sell.
Current price per share: The current market price per share at which you expect to sell. This drives both your total proceeds and the size of your gain relative to your purchase price.
Shares: The number of shares you plan to sell as part of this harvest. If you are only partially harvesting a position, enter the subset of shares you intend to realize gains on.
Capital gains tax rate (%): A single effective tax rate you want to apply to the realized gain. You can approximate your combined federal, state, and surtax rate here, or use just the federal long‑term rate if you prefer a narrower view.

Outputs explained

Gain per share: The dollar gain on each share sold, calculated as current price minus purchase price (floored at zero in this simplified view). This highlights how much value has built up per share.
Total gain: Your aggregate realized capital gain for this harvest, equal to gain per share times the number of shares sold. This is the amount we apply your effective tax rate to.
Estimated tax: An estimate of the tax you might owe on the realized gain if it is taxed at your entered capital gains rate. Actual tax will depend on holding period, brackets, and other factors.
Net proceeds after tax: The cash you would have left after paying the estimated tax, calculated as current price × shares minus the estimated tax. This is a rough sense of what you could reinvest or spend after a harvest.

How it works

We start by computing gain per share as the difference between the current price and your original purchase price. If the current price is at or below purchase price, gain per share is treated as zero for this simple harvest view.

Total gain is gain per share multiplied by the number of shares you plan to sell. This represents the dollar amount of capital gain you would realize in the harvest.

Estimated tax is calculated by multiplying the total gain by your entered capital gains tax rate (expressed as a single effective rate that can blend federal, state, and NIIT if you choose).

Gross proceeds from the sale are the current price multiplied by the number of shares. Net proceeds after tax are gross proceeds minus the estimated tax on the gain.

The calculator does not distinguish between short‑term and long‑term holding periods or tax brackets; instead, it lets you plug in the effective rate that best approximates your situation for a quick planning estimate.

Formula

Let P₀ be purchase price, P₁ be current price, N be the number of shares, and r be the effective capital gains tax rate as a decimal.\n\n• Gain per share = max(P₁ − P₀, 0)\n• Total gain = Gain per share × N\n• Estimated tax = Total gain × r\n• Gross proceeds = P₁ × N\n• Net proceeds after tax = Gross proceeds − Estimated tax

When to use it

Planning a year‑end capital gains harvest to make use of a low capital gains bracket or to realize gains up to a strategic threshold.
Comparing different harvest amounts or prices to see how much additional tax you would incur and how much net cash you would receive.
Evaluating whether harvesting gains makes sense before potential tax law changes or expected income increases in future years.
Planning a portfolio rebalance or diversification move by estimating the tax cost of trimming a concentrated stock position.
Pairing with a tax‑loss harvesting strategy to see how realized losses in other holdings can offset the gains you harvest here.

Tips & cautions

Use a long‑term capital gains rate if you have held the asset for more than one year and expect it to be taxed at favorable long‑term rates; use a higher rate if you expect short‑term treatment.
Consider including state and local taxes and any applicable surtaxes in your effective rate input so that the estimated tax better matches your total liability.
If you have realized capital losses elsewhere in your portfolio, you can conceptually apply those against gains when deciding how much to harvest; this calculator assumes you enter an effective gain figure via cost and price.
Remember that realizing gains may also affect other parts of your tax picture—such as phaseouts, Medicare premiums, or credits—beyond the simple capital gains tax itself.
Run multiple scenarios with different prices and share counts to understand your flexibility around how much gain to realize in the current year versus deferring to a future year.
Uses a single effective tax rate and does not model tiered brackets, different rates for qualified dividends vs capital gains, or separate short‑term and long‑term buckets.
Does not distinguish among tax lots, lot selection methods (FIFO, LIFO, specific identification), or different holding periods across lots.
Does not automatically incorporate tax‑loss harvesting, wash sale rules, or the impact of other income and deductions on your actual marginal rate.
State, local, and surtaxes are not modeled separately; they must be approximated inside the single rate input if you want them included.
Outputs are simplified planning estimates only and are not suitable for preparing a tax return or making irreversible tax decisions without professional guidance.

Worked examples

Example 1: Buy at $200, sell at $250, 100 shares, 15% rate

Purchase price P₀ = $200; current price P₁ = $250; N = 100; r = 15% (0.15).
Gain per share = 250 − 200 = $50.
Total gain = $50 × 100 = $5,000.
Estimated tax = $5,000 × 0.15 = $750.
Gross proceeds = $250 × 100 = $25,000; Net proceeds after tax = $25,000 − $750 = $24,250.

Example 2: Buy at $20, sell at $30, 1,000 shares, 20% rate

P₀ = $20; P₁ = $30; N = 1,000; r = 20% (0.20).
Gain per share = 30 − 20 = $10.
Total gain = $10 × 1,000 = $10,000.
Estimated tax = $10,000 × 0.20 = $2,000.
Gross proceeds = $30 × 1,000 = $30,000; Net proceeds after tax = $30,000 − $2,000 = $28,000.

Example 3: No gain scenario (current price below purchase price)

P₀ = $50; P₁ = $45; N = 200; r = 15% (0.15).
Gain per share = max(45 − 50, 0) = 0 (no gain in this simplified model).
Total gain = 0 × 200 = $0; Estimated tax = $0 × 0.15 = $0.
Gross proceeds = $45 × 200 = $9,000; Net proceeds after tax = $9,000.
Interpretation: in this simple gain‑focused calculator, there is no taxable gain. In reality, this could represent a capital loss that might offset other gains.

Deep dive

Use this capital gains harvest calculator to estimate how much gain you would realize, how much tax you might owe, and how much cash you would keep after selling appreciated investments at today’s price.

By adjusting purchase price, current price, shares, and an effective capital gains rate, you can explore different harvest scenarios, compare year‑by‑year timing options, and better understand the trade‑off between locking in gains and incurring taxes now versus later.

Combine this tool with broader tax planning—such as bracket management, tax‑loss harvesting, and diversification goals—to make more informed decisions about when and how much to harvest from your taxable investment accounts.

FAQs

Does this calculator distinguish between short‑term and long‑term capital gains?: No. It uses a single effective rate you provide. To approximate short‑term or long‑term treatment, choose a rate that reflects how the sale will likely be taxed, or run separate scenarios with different rates.
Can I include state tax, NIIT, or other surtaxes in the estimate?: Yes. Combine your expected federal, state, and surtax percentages into one effective rate and enter that figure. The calculator will then approximate your total tax on the gain using that rate.
Does this handle multiple tax lots or specific identification of lots?: No. It assumes a single purchase price and current price for the shares you enter. For portfolios with many lots and different holding periods, you may want to approximate using a weighted average or run separate calculations for each lot.
How should I think about tax‑loss harvesting with this tool?: This calculator focuses on realized gains from a sale. To see the net effect of pairing gains and losses, you can conceptually offset gains with realized losses when choosing how many shares to harvest or adjust your effective rate to reflect reduced taxable gains.
Is this capital gains harvest calculator tax or investment advice?: No. It is an educational estimate only and does not capture all tax rules, interactions, or personal circumstances. Use it as a starting point for planning, then confirm any harvest strategy with a qualified tax professional or financial advisor.

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This capital gains harvest calculator provides a simplified estimate of gains, taxes, and net proceeds based on user‑entered prices, share counts, and an effective tax rate. It does not model detailed tax brackets, lot selection, holding periods, wash rules, or interactions with other parts of the tax code and is not tax, legal, or investment advice. Always review harvest decisions with a qualified professional and refer to official tax guidance for actual filing.