Selling Part of Your ETH: How to Work Out the Remaining Profit

If you sell only part of your ETH, calculate the result in two separate pieces: the profit realized on the ETH you sold and the unrealized profit or loss still attached to the ETH you hold. The basic calculation is realized sale proceeds minus the cost basis of the units sold and any selling costs. For the ETH that remains, subtract its remaining cost basis from its current market value, while recognizing that the market value changes over time.

This distinction matters because a partial sale does not turn the entire position into a profit or loss. Some of your original investment has been converted into cash or another asset, while the rest remains exposed to ETH price movements. The calculation also depends on how you assign cost basis to the ETH sold, such as first in, first out (FIFO), specific identification, or another method that may apply in your jurisdiction. This article is for education, not personalized investment or tax advice.

The two numbers you need to calculate

After a partial ETH sale, there are usually two different performance figures:

• Realized profit or loss: The gain or loss associated with the ETH that was sold.
• Unrealized profit or loss: The current gain or loss on the ETH that remains in your wallet or account.

You can also combine them to estimate the position's total profit or loss to date. That combined figure compares the cash or other proceeds already received plus the current value of the remaining ETH with the total cost of the original position. It should include applicable trading, network, withdrawal, and other transaction costs when those costs are known.

Core formulas for a partial ETH sale

Realized profit or loss

The general formula is:

Realized profit or loss = net sale proceeds − cost basis of ETH sold

Net sale proceeds are the amount you receive after subtracting selling fees and any other directly related costs. If your exchange displays a gross order value and a separate fee, use the amount actually credited after the fee rather than the gross value.

The cost basis of the ETH sold is the original purchase cost assigned to those specific units, adjusted for relevant acquisition costs and other items that may affect basis. If you bought ETH in several transactions, you cannot calculate the result accurately without deciding which units were sold under the accounting method you use.

Remaining cost basis

Once you identify the basis assigned to the sold ETH, calculate the basis still attached to the holding:

Remaining cost basis = total original cost basis − cost basis of ETH sold

This is not necessarily the same as the current value of the ETH you still hold. Cost basis is a historical accounting figure. Current value is based on the market price and can change continuously.

Unrealized profit or loss

For the ETH that remains:

Unrealized profit or loss = current value of remaining ETH − remaining cost basis

To estimate current value, multiply the remaining ETH amount by a current ETH price:

Current value = remaining ETH × current ETH price

Because crypto prices are time-sensitive, record the price source and timestamp used for the calculation. An exchange price, index price, and quoted conversion rate may differ slightly. You can use the Crypto Profit Calculator to test a scenario, but confirm that its inputs match your transaction records and accounting assumptions.

An illustrative example

Assume the following hypothetical position:

• You bought 2 ETH for a total cost of $3,000.
• Your average purchase cost was therefore $1,500 per ETH.
• You later sell 0.75 ETH for $2,250 before a $22.50 selling fee.
• For this simplified example, assume the 0.75 ETH sold carries a basis of $1,125.
• You still hold 1.25 ETH.

The net sale proceeds are $2,227.50:

$2,250 − $22.50 = $2,227.50

The realized profit is:

$2,227.50 − $1,125 = $1,102.50

The remaining cost basis is:

$3,000 − $1,125 = $1,875

Now suppose, only for illustration, that the current ETH price is $2,400. The remaining ETH has a current value of:

1.25 × $2,400 = $3,000

Its unrealized profit is:

$3,000 − $1,875 = $1,125

The estimated combined profit is the realized profit plus the unrealized profit:

$1,102.50 + $1,125 = $2,227.50

This example uses simple assumptions and is not a prediction of ETH's price or a statement about any actual return. If the market price falls, the unrealized amount falls. If it rises, the unrealized amount rises, before considering additional costs and any tax consequences.

Why average cost can be misleading

Dividing total spending by total ETH purchased produces an average cost per ETH, which can be useful for a quick estimate. However, it may not be the correct basis method for a particular recordkeeping or tax situation. Suppose you bought ETH at several different prices and then sold part of the position. The profit may differ depending on whether the units sold are matched to earlier purchases, later purchases, or specifically identified units.

For example, consider two hypothetical lots:

• Lot A: 0.5 ETH purchased for $800.
• Lot B: 1 ETH purchased for $2,200.

If you sell 0.5 ETH, assigning the sale to Lot A produces a different realized result than assigning it to Lot B. The amount of ETH sold is the same, but the assigned basis is different. Keep purchase confirmations, wallet transfers, exchange statements, and records showing which units were sold. If you are calculating a reportable gain or loss, ask a qualified tax professional which identification and accounting rules apply to your situation. Tax treatment is jurisdiction-specific and time-sensitive.

Include fees and transfers carefully

Fees can affect both the sale proceeds and the quantity of ETH remaining. A trading fee may be charged in dollars, ETH, or another asset. A network fee may be paid when moving ETH between wallets. Platform charges can also vary by account, order type, payment method, and provider.

Do not assume that every fee should be handled in exactly the same way. For a performance estimate, subtract costs that reduce your proceeds or increase your total investment. For tax reporting, the treatment may depend on the nature of the fee and local rules. Your exchange's displayed execution price may not equal the final amount after fees, spread, and slippage.

To improve accuracy, record:

• The date and time of each purchase and sale.
• The ETH amount before and after the transaction.
• The gross proceeds and the fee currency.
• The net proceeds actually received.
• The wallet or exchange involved.
• The cost basis assigned to the units sold.
• The price source and timestamp used for any current-value estimate.

If you want to isolate transaction costs, the Crypto Fee Calculator can help you model fee effects. Treat its output as an estimate unless it uses the exact fee schedule and transaction data from your provider.

How to calculate total position performance

Another useful approach is to compare what you have now with what you originally put in. The formula is:

Total estimated profit or loss = net proceeds already received + current value of remaining ETH − total original cost basis

Using the illustrative example:

• Net proceeds already received: $2,227.50.
• Current value of remaining ETH: $3,000.
• Total original cost basis: $3,000.

$2,227.50 + $3,000 − $3,000 = $2,227.50

This method is useful for reviewing the entire position, but it does not replace the separate realized and unrealized figures. Those separate amounts show which portion has already been converted into proceeds and which portion still depends on ETH's future price.

Common mistakes to avoid

Counting the sale proceeds as pure profit

Receiving money from a sale does not mean the entire amount is profit. The sold ETH had an assigned cost basis, which must be subtracted from net proceeds.

Using today's price for the realized calculation

The realized result generally uses the actual execution price and actual costs from the sale. A current price is relevant to the remaining ETH, not to the historical sale unless you are modeling a hypothetical transaction.

Ignoring the units sold

Record the exact ETH amount sold. Rounding a transaction too early can create discrepancies, especially when multiple partial sales occur.

Resetting the basis incorrectly

After a sale, do not simply multiply the remaining ETH by the old average purchase price unless that assumption is appropriate for your records. Recalculate the remaining basis using the units and lots actually assigned to the sale.

Mixing investment performance with tax reporting

A personal performance estimate and a tax calculation may use different inputs or conventions. Tax rules can change, and treatment may depend on your location, transaction history, holding period, and the type of activity involved. Verify current requirements with an official tax authority or a qualified professional.

Using a calculator without losing the assumptions

A calculator is most useful when it makes the assumptions visible. Before entering numbers, decide whether you are calculating realized profit, unrealized profit, total position performance, or all three. Then enter the ETH amount sold, the net sale proceeds, the assigned cost basis, the remaining ETH amount, the current price, and relevant fees.

For currency conversions, prices can vary between providers and timestamps. A Crypto Converter can help with a quick estimate, but preserve the original transaction currency and exchange rate used in your records. If you made recurring purchases, a Crypto DCA Calculator may help summarize average acquisition cost, although it may not determine the correct lot assignment for a partial sale.

A practical checklist before you finalize the result

1. Confirm the exact amount of ETH sold and the amount remaining.
2. Use actual net proceeds rather than a gross order value.
3. Choose and document the cost-basis method used for the sold units.
4. Separate realized profit from unrealized profit.
5. Include fees consistently and avoid double-counting them.
6. Label current-value figures with the price source and timestamp.
7. Save transaction records and review any tax or reporting questions with a qualified professional.

A partial ETH sale can therefore be evaluated without treating the entire position as closed. Start with the units sold and their assigned basis, calculate the realized result using net proceeds, then value the ETH that remains against its remaining basis. Keeping those calculations separate gives you a clearer view of what has already happened and what still depends on a volatile market.