This tool answers a narrower question than a exchange app's paper-gain display: after paying to buy, paying to sell, and settling up with the tax office, how much of a crypto trade's headline gain actually survives? Round-trip trading fees and a gains tax bill routinely eat a third or more of what looked like a doubling on the price chart, and the break-even sell price it produces is the number that tells you whether you are still underwater before you even open the tax question.
Reading the break-even sell price
Break-even here is not the price you paid. It is that price grossed up by the fee charged on both the purchase and the eventual sale, since both legs cost money regardless of which way the trade goes. Buy at 20,000 with a 1% fee each way and the coin has to reach 20,200 before you have your capital back, even before any tax is owed on the difference.
A wider spread between your buy fee and your break-even price signals a venue charging more than the advertised headline rate, often through a spread markup on top of a stated commission. Comparing the break-even figure across two exchanges for the identical trade size is a cleaner test of true cost than comparing their published fee percentages.
Tax only bites once you are past break-even, since a loss carries no tax in almost every regime this tool models. That means the break-even line marks the point where your risk profile changes from pure downside to a shared-upside position with the tax authority.
Three trades, worked through
Put 10,000 into a coin at 20,000 and sell the position at 30,000, with a 1% fee on each leg and 15% tax on the gain. Units bought equal 0.5, the sale is worth 15,000, both-way fees total 250, and the gain before tax is 4,750. Tax of 712.50 leaves a net profit of 4,037.50 — a 40.4% return on the 10,000 staked, well short of the 50% the raw price move suggests.
Now take a losing trade: 2,000 into a coin at 60,000, sold at 52,000, with a 0.75% fee each way and a 20% tax rate. Units bought are about 0.0333, the sale raises 1,733, fees run to roughly 28, and the position closes at a loss of about 295 before any tax — and a loss owes no tax, so 295 is also the final number. The break-even price on this trade was 60,450, meaning the coin needed to rise before you would have owed anything at all.
For a bigger, longer-held position: 25,000 into a coin priced at 1,800 a unit, sold later at 3,200, with a light 0.25% fee each way and 24% tax on the gain. Units bought come to about 13.89, the sale is worth roughly 44,444, fees total about 174, pre-tax gain is around 19,271, tax at 24% is about 4,625, and net profit lands near 14,646 — a 58.6% return, versus a 78% raw price gain from 1,800 to 3,200.
What the model quietly assumes
It treats the trade as a single lot bought once and sold once, with one fee rate applied to the whole entry and the whole exit. Anyone who bought in stages, or who is selling only part of a larger holding, needs to run each lot separately and use the specific cost basis for that lot, not an average across every purchase.
It also assumes fees are charged as a flat percentage of trade value. Network gas fees on-chain, withdrawal fees, and the wider bid-ask spread on thinly traded pairs are real costs that do not show up in an exchange's quoted maker or taker rate, so the actual break-even for a self-custody trade is usually a little higher than this figure implies.
The single tax-rate slider is a simplification of a system that, in most countries, actually depends on how long you held the coin, your total income for the year, and whether the trade nets against other losses. A single flat rate is a reasonable estimate for a rough check, not a substitute for running the actual figures through the method your tax authority requires.
Where the tax rules diverge by country
In the United States, the IRS treats crypto as property: a sale held over one year gets the lower long-term capital gains rate, while a sale within a year is taxed as ordinary income, and every disposal — including a crypto-to-crypto swap, not just a cash-out — is a taxable event that must be reported.
In the United Kingdom, individuals pay capital gains tax on disposals above the annual exempt amount, which HMRC has cut sharply in recent tax years, and gains from crypto sit inside the same allowance as gains from shares or a second property rather than having a pot of their own.
Several jurisdictions tax mining and staking rewards as income at the point received and then apply capital gains rules again on a later sale, which stacks two separate tax events onto a single coin. If any of the units you are modelling came from staking or an airdrop rather than a purchase, this tool's single buy price will understate what you actually owe.
Timing decisions the calculator cannot make for you
Selling a few days before a tax year's anniversary of purchase can be the difference between a short-term and a long-term rate in countries that split the two, and that gap is frequently worth more than a modest further price move either way.
Realising a loss deliberately, sometimes called tax-loss harvesting, can offset a gain elsewhere in the same tax year, but a wash-sale-style rule in some jurisdictions blocks repurchasing the same asset within a set window and still claiming the loss — check the local rule before repurchasing the coin you just sold at a loss.
Exchange rate movements matter too if your reporting currency differs from the currency you traded in: a flat coin price against a weakening home currency can still register as a taxable gain once converted for the tax return, even though nothing changed in dollar or coin terms.
Frequently asked questions
- Is a crypto-to-crypto swap taxable, or only a cash-out?
- In the US and UK, swapping one coin for another is treated as disposing of the first coin at its market value in your home currency, so it is taxable at the moment of the swap even though no cash reached a bank account. Model the swap as a sale at that market value, not as a hold.
- Do I owe tax on a crypto loss?
- No tax is due on a loss itself, and this tool sets tax to zero whenever the pre-tax gain is negative. The loss can usually be used to offset a gain elsewhere in the same tax year, subject to the reporting rules your country applies to capital losses.
- Why is my break-even price higher than what I paid?
- Because the fee on the eventual sale is added on top of the fee you already paid to buy. A 1% fee on each leg means the coin has to rise about 2% above your purchase price, not 1%, before the trade is even net-zero.
- Does holding longer always lower the tax rate?
- Only in systems built around a holding-period split, such as the US line between short-term and long-term capital gains at the one-year mark. Flat-rate systems and income-tax-style regimes do not reward holding length the same way, so check which system applies before timing a sale around it.
- How do exchange and network fees affect the number this tool gives?
- The tool applies one percentage fee to both the buy and the sell leg. Gas fees for an on-chain transfer, a separate withdrawal fee, or a wide spread on a thin trading pair are not included, so a self-custody trade's real break-even sits a little above the figure the calculator returns.
- What records do I need to keep for a crypto trade?
- Keep the date, amount, price in your home currency, and fee for every buy and every sell, plus the wallet or exchange each trade ran through. Tax authorities that require gain reporting, including the IRS, expect this level of detail per lot rather than a single average cost across a whole holding.
Sources
- IRS — Digital Assets guidance — Confirms crypto-to-crypto trades and disposals are taxable events, and that holding period determines short-term versus long-term capital gains treatment (guidance current as of the 2025 filing season).
- HMRC — Cryptoassets Manual — Sets out that UK individuals pay capital gains tax on disposals of cryptoassets within the same annual exempt amount as other capital gains, and covers the separate income tax treatment of mining and staking rewards.