Crypto Position Sizing, Fees, and Break-Even: A Complete Guide

Position sizing is the most important risk management tool in trading. It answers: "How much should I buy?"

The standard formula:

Position Size = (Account Size × Risk %) / (Entry Price − Stop-Loss Price)

Example: $10,000 portfolio, 2% risk per trade, buying Bitcoin at $40,000 with a stop-loss at $38,000:

Position Size = ($10,000 × 0.02) / ($40,000 − $38,000)

Position Size = $200 / $2,000 = 0.1 BTC ($4,000)

This means you risk exactly $200 (2% of your portfolio) if your stop-loss triggers. Never risk more than 1-2% of your portfolio on a single trade — this ensures that even a string of losses won't destroy your account.

Crypto trading fees add up faster than most people realize:

Common fee structures:

• Centralized exchanges (Binance, Coinbase Pro): 0.1–0.5% per trade
• Coinbase (simple buy): 1.0–1.5% per trade
• Decentralized exchanges (Uniswap): 0.3% + gas fees
• Spread costs: 0.5–2.0% on some platforms

Since you pay fees on both buying and selling, the round-trip cost doubles:

• Buy $5,000 of ETH at 0.5% fee = $25
• Sell $5,000 of ETH at 0.5% fee = $25
• Total round-trip cost: $50 (1.0%)

For a day trader making 200 trades per month at 0.2% per trade:

200 × 0.2% × 2 (round-trip) = 80% of capital lost to fees annually

This is why most day traders lose money. Fee-aware position sizing is critical.

Break-even price accounts for all costs of entering and exiting a trade:

Break-Even = Entry Price × (1 + Buy Fee + Sell Fee)

Example: Buy 1 ETH at $3,000 with 0.5% fees on each side:

Break-Even = $3,000 × (1 + 0.005 + 0.005)

Break-Even = $3,000 × 1.01 = $3,030

ETH needs to rise 1% ($30) just to cover fees.

With leverage (e.g., 5x):

Fees are charged on the leveraged amount, not your margin. A 0.1% fee on a 5x leveraged $10,000 position means fees on $50,000 = $50 each way.

Break-even moves further from your entry, making leveraged trading even more fee-sensitive.

Always calculate break-even before entering a trade. If the expected move is smaller than your break-even spread, the trade has negative expected value.

Crypto is the most volatile major asset class. Risk management is non-negotiable:

The 1-2% Rule

Never risk more than 1-2% of your total portfolio on a single trade. With a $10,000 account, your maximum loss per trade is $100-$200.

Always use stop-losses

Set stop-losses before entering a trade, not after. Move stops up to lock in profits, never down to avoid losses.

The fee-adjusted profit target

If fees cost 1% round-trip, your minimum profit target should be at least 3% to maintain a 2:1 reward-to-risk ratio after costs.

Portfolio allocation limits

• Keep no more than 5-10% of your total investment portfolio in crypto
• Diversify across multiple coins — don't put everything in one token
• Hold stablecoins as dry powder for buying opportunities

The golden rule: Never invest money you can't afford to lose entirely. Crypto can drop 50-80% in a bear market.