Gross vs net P&L: how commission and swap change your results

Many traders judge their results on the profit column of their platform. That number is often gross: the price movement of the trade, before commission and before overnight swap. What reaches your account is the net figure, after those costs.

For a trader who holds a few positions a week, the gap may be small. For a scalper or a high-frequency day trader, it can turn a profitable month into a losing one. This guide explains what to count, how to measure it, and how to tell when costs are the problem.

What counts as a trading cost

Cost	What it is	Where it usually appears
Commission	A fee per trade or per lot, charged by brokers on raw-spread or ECN-style accounts	Its own column in most trade history reports
Swap (rollover)	Financing charged or paid for holding a position overnight. Depends on the instrument, direction and the broker's rates; can be negative or positive	Its own column in most trade history reports
Spread	The difference between the bid and ask price	Already inside your entry and exit prices, so already inside the gross profit. Do not subtract it again

So, for most forex and CFD accounts:

Net P&L = gross P&L + commission + swap

where commission and swap are entered with their sign (a charge is negative; a swap credit is positive).

Why the gap grows with trade frequency

A cost per trade is fixed no matter how much the trade makes. The smaller your average result per trade, the larger the share costs take.

A hypothetical month (an illustration, not real account data):

• 300 trades, each 0.5 lots
• Gross result: +$600, so about +$2 per trade
• Commission: suppose the broker charges $7 per lot round turn

Commission = 300 × 0.5 × $7 = $1,050. Net result = $600 − $1,050 = −$450, before any swap.

The trading itself was positive. The account went down. Nothing in the gross numbers would warn you.

Compare a swing trader with 20 trades a month at 1 lot, with the same commission: 20 × 1 × $7 = $140 in commission. On a gross result of +$600, that leaves +$460. Same costs per lot, very different weight.

Two numbers to calculate

1. Average cost per trade

Average cost per trade = (total commission + total swap charged) ÷ number of trades

Compare it with your average gross result per trade. If costs are a large part of it, small changes in costs matter as much as small changes in your trading.

2. Cost share of gross profit

Cost share = total costs ÷ gross P&L (only meaningful when gross P&L is positive)

In the scalping example: $1,050 ÷ $600 = 175%. Costs were larger than everything the trading earned. In the swing example: $140 ÷ $600 = 23%.

There is no universal "good" level, but a cost share that keeps rising as you trade more often is a clear signal to look at trade frequency.

Costs also move your break-even win rate

Because costs make every win smaller and every loss larger, they raise the win rate you need just to break even. A trader can be above the line before costs and below it after. We walk through the formula and an example in high win rate but still losing money.

How to check your own history

1. Export closed trades from your platform as a file, for a period of at least a few weeks.
2. Find the cost columns. Most history reports list commission and swap separately from profit. If commission is reported somewhere else (some brokers report it in a separate statement), add it in.
3. Sum three columns: gross profit, commission, swap. Net = gross + commission + swap.
4. Calculate average cost per trade and cost share of gross profit.
5. Split by style. Compare short-hold trades with longer ones, or one symbol with another. Costs often concentrate in one part of a history.

What you can change

These are options to test against your own data, not recommendations for every trader:

• Fewer, higher-quality trades. If cost share is high, cutting the weakest trades can raise net results even if gross results fall a little.
• Larger targets relative to cost. A cost that is 30% of a small target may be 5% of a larger one.
• Account type. Raw-spread accounts with commission and standard accounts with wider spreads price costs differently. Compare total cost on your own typical trade, not the headline numbers.
• Swap awareness. If you hold overnight, check the swap rates for your instruments and direction; some carry positions earn a credit, others pay every night.

Key points

• The spread is already inside your prices. Commission and swap usually are not.
• Net P&L = gross P&L + commission + swap (with their signs).
• The more often you trade and the smaller your targets, the more costs decide your result.
• Measure average cost per trade and cost share of gross profit before you change your strategy.
• Calculate expectancy and break-even win rate on net results. See how to calculate trading expectancy.

Where TradeYar fits: when you import a broker file, TradeYar reads commission and swap and computes net P&L for every trade. The free dashboard's net P&L and expectancy are after these costs; profit factor follows the usual convention and is computed on gross results. The Pro Performance Hub adds a Fee Drag card with your total cost and average cost per trade.