Introduction
A position size calculator helps you figure out how many shares, lots, or contracts to buy or sell in a trade. It uses your account balance, the amount you are willing to risk, your entry price, and your stop loss to give you the right trade size. Getting your position size right is one of the most important parts of trading because it keeps you from losing too much money on a single trade.
This free calculator works for stocks, forex, crypto, and futures. You can set your risk as a percentage of your account or as a fixed dollar amount. It also calculates your risk-to-reward ratio when you add a take profit price. Whether you are a beginner or an experienced trader, this tool makes it simple to manage your risk and protect your capital before you enter any trade. For forex-specific profit calculations, you may also want to check out our Forex Profit Calculator.
How to Use Our Position Size Calculator
Enter your account details, risk preferences, and trade levels below. The calculator will tell you how many shares, lots, or contracts to buy, how much money is at risk, and your risk-to-reward ratio.
Asset Class: Pick the type of market you are trading. Choose from Stocks, Forex, Crypto, or Futures.
Trade Direction: Select Long if you expect the price to go up. Select Short if you expect the price to go down.
Account Balance: Type in the total amount of money in your trading account. If you need help tracking your overall finances, our Net Worth Calculator can give you a complete picture of your financial standing.
Account Currency: Choose the currency your trading account is held in, such as USD, EUR, or GBP.
Risk Mode: Pick how you want to set your risk. Use percent to risk a percentage of your account, fixed to risk an exact dollar amount, or lots if you trade forex and already know your lot size.
Currency Pair: If you chose Forex, search for and select the currency pair you want to trade. The calculator will load a reference rate for you.
Symbol / Ticker: If you chose Stocks, Crypto, or Futures, type in the name or ticker of the asset you are trading.
Tick Value: If you chose Futures, enter the dollar value of a one-point move per contract. For example, the E-mini S&P 500 has a tick value of $50 per point.
Entry Price: Enter the price where you plan to open your trade. You can also click "Use Live Price" to fill in an estimated current price.
Stop Loss: Set where you will exit the trade if it goes against you. You can enter a specific price or a number of pips or points away from your entry.
Take Profit: Check the box and enter a target price where you plan to take your profits. This is optional but lets the calculator show your risk-to-reward ratio.
Calculate Button: Click this button to see your results. The calculator will show your position size, position value, amount at risk, risk-to-reward ratio, and a bar chart comparing your potential loss to your potential gain.
Reset Button: Click this button to clear all fields and start over with the default values.
What Is a Position Size Calculator?
A position size calculator tells you how many shares, lots, or contracts to buy or sell in a trade based on how much money you are willing to lose. It is one of the most important tools in risk management. Instead of guessing how big your trade should be, this calculator does the math for you so you never risk more than you planned.
Why Position Sizing Matters
Every trade has a chance of losing money. Position sizing controls how much you lose when a trade goes wrong. If you risk too much on one trade, a single loss can wipe out a big chunk of your account. If you risk a small, fixed percentage each time, your account can survive a string of losses and still recover. Most professional traders risk between 1% and 2% of their account per trade. Understanding your overall return on investment across all your trades is just as important as managing individual position sizes.
How It Works
The calculator uses three key pieces of information to find your position size:
- Account balance – the total money in your trading account.
- Risk amount – the most you are willing to lose on this trade, set as a percentage of your balance or a fixed dollar amount.
- Stop loss distance – the gap between your entry price and your stop loss price. This is how far the price must move against you before you exit the trade.
The basic formula is: Position Size = Risk Amount ÷ Stop Loss Distance. For example, if your account is $10,000, you risk 1% ($100), and your stop loss is $5 away from your entry, you would buy 20 shares. If you want to calculate profits on stock trades after determining your position size, try our Stock Profit Calculator.
Asset Classes Supported
This calculator works for stocks, forex, crypto, and futures. Each asset class sizes positions a little differently. Stocks and crypto use share or unit counts. Forex uses lots, where one standard lot equals 100,000 currency units. Futures use contracts, and each contract has a fixed dollar value per point of price movement called the tick value. For crypto traders looking to track gains over time with a regular buying strategy, our DCA Calculator is a helpful companion tool. If you are focused on crypto gains from a specific trade, the Crypto Profit Calculator can help with that.
Risk-to-Reward Ratio
When you set a take profit price, the calculator also shows your risk-to-reward ratio. This ratio compares how much you could lose to how much you could gain. A ratio of 1:2 means you stand to make twice what you risk. Traders generally look for setups where the reward is at least equal to or greater than the risk. You can use our Ratio Calculator to explore ratio math in more detail. For options traders who need to evaluate potential profit and loss scenarios, our Options Profit Calculator provides a dedicated analysis tool. Once your trades generate returns, tools like the Compound Interest Calculator and Investment Calculator can help you plan how to grow those profits over time.