Position sizing for beginners
New traders spend most of their time picking what to buy. The pros spend most of their time deciding how much. Position sizing is the difference between a hobby and a process.
What position sizing is
Position sizing is deciding how much of your money to put into a single trade. It is not the same as picking a stock or a coin. The pick tells you what to buy. The size tells you how many shares, lots, or units.
Most traders learn to pick before they learn to size. That is backwards. A great pick with a bad size can still lose you money. A normal pick with a good size keeps you in the game.
Why it matters more than picking
Trading is a game of survival. If you lose half your account, you have to double the rest just to break even. Big losses are very hard to recover from. The math:
- Lose 10 percent. You need to gain 11 percent to recover.
- Lose 25 percent. You need to gain 33 percent to recover.
- Lose 50 percent. You need to gain 100 percent to recover.
- Lose 75 percent. You need to gain 300 percent to recover.
Good position sizing keeps any single loss small. That keeps the recovery math reasonable.
The basic formula
The standard position sizing formula has three inputs:
- Your account size in money.
- The percent of your account you are willing to risk on this trade.
- The distance, in price, from your entry to your stop loss.
The formula:
Position size = (Account size × Risk percent) ÷ Stop distance
Risk percent is usually a small number, like 1 percent. Stop distance is in the same units as the price. CalcMyTrade does this math instantly across stocks, forex, and crypto with the correct units for each market.
Worked examples
Stocks
You have a $10,000 account. You will risk 1 percent per trade, which is $100. You want to buy a stock at $50. Your stop loss is at $48. The stop distance is $2 per share.
Position size = $100 divided by $2 = 50 shares.
Total cost of the trade is 50 shares times $50 = $2,500. That is 25 percent of your account, but the risk is only 1 percent because you have a stop in place.
Forex
You have a $5,000 account. You will risk 1 percent, which is $50. You go long EURUSD at 1.1000 with a stop at 1.0950. The stop distance is 50 pips.
For a standard lot of 100,000 units on EURUSD, each pip is worth $10. For a mini lot of 10,000 units, each pip is worth $1. For a micro lot of 1,000 units, each pip is worth $0.10.
Position size = $50 divided by 50 pips = $1 per pip. That is one mini lot, or 0.10 of a standard lot.
Crypto
You have a $20,000 account. You will risk 1 percent, which is $200. You buy Bitcoin at $60,000 with a stop at $58,000. The stop distance is $2,000 per coin.
Position size = $200 divided by $2,000 = 0.1 BTC.
Total cost of the trade is 0.1 BTC times $60,000 = $6,000. The risk is still capped at $200.
Common mistakes
- Using a percent that is too big. A new trader risking 5 percent a trade can blow up in a week.
- Skipping the stop loss. Without a stop, you cannot calculate position size. Without a position size, you are gambling.
- Moving the stop after entry. The stop is part of the math. Moving it later breaks the plan.
- Sizing by gut. Once you have a formula, use it. Always.
- Forgetting fees. On small accounts, fees can change the real risk by a noticeable amount.
How position sizing protects you
A 1 percent rule with a 50 percent win rate, a one to one reward to risk, and reasonable consistency keeps you trading for years. Bigger risk percentages can lead to faster gains in good runs, but the bad runs hit hard. Most pros risk between 0.5 and 2 percent per trade.
Putting it together
- Pick your risk percent. For beginners, 0.5 to 1 percent is wise.
- For every trade, write down your entry, stop, and target before you take the trade.
- Use CalcMyTrade to compute the size.
- Take the trade exactly as planned.
- Review your trades weekly to see what is working.
Position sizing is not glamorous. It is the foundation that makes everything else possible. Get this right and the rest of trading becomes easier.