Position Size Calculator

1. Enter your account size, your total trading capital.
2. Enter the risk per trade as a percentage, often 1 to 2%.
3. Enter your entry price and your stop-loss price.
4. Read your position size, the amount at risk and the position value.

Here is what each result means:

Position sizing is deciding how much to buy on a trade so that a loss is controlled. Instead of picking a share count at random, you fix the money you are willing to lose, then let your stop-loss distance set the size. It is the core of risk management and the main thing that keeps a run of losses from wiping out an account.

The idea is simple: risk a small, fixed share of your capital on each trade, commonly 1 to 2 percent, so no single trade can do serious damage. The wider your stop, the smaller the position; the tighter your stop, the larger it can be for the same risk.

It turns your fixed risk amount and your stop distance into a share count, so a stop-out costs exactly your chosen risk.

1. Multiply your account by the risk percent to get the risk amount.
2. Find the risk per share: the distance from entry to stop-loss.
3. Divide the risk amount by the risk per share for the position size.

Suppose your account is 10,000, you risk 1%, your entry is 50 and your stop-loss is 48.

Calculation: risk amount = 10,000 x 1% = 100. Risk per share = 50 - 48 = 2. Shares = 100 / 2 = 50. Position value = 50 x 50 = 2,500.

If the stop is hit, you lose 50 shares x 2 = 100, exactly 1 percent of the account. A tighter stop at 49 would allow 100 shares for the same 100 risk, and a wider stop at 45 would allow only 20.

The risk percent is the dial that controls how aggressive your sizing is.

Most professionals keep per-trade risk at 1 to 2 percent so a losing streak is survivable. The figures above are approximate and assume you keep risking the same percent of a shrinking account.

Your Stop Distance

A wider stop means a smaller position for the same risk, and a tighter stop means a larger one. The stop, not the entry, does most of the work.

Your Risk Percent

Doubling your risk percent doubles the position for the same stop. This is the fastest way to change exposure, and the most dangerous.

Your Account Size

As your account grows or shrinks, the same risk percent scales the position up or down automatically.

Before Every Trade

Set your size from your risk and stop rather than guessing a share count.

Comparing Setups

See how a tighter or wider stop changes how much you can buy for the same risk.

Managing an Account

Keep every trade to the same fixed risk so no single loss is outsized. Track results with the ROI calculator.

1. Sizing by Gut, Not by Risk

Picking a round share count ignores your stop distance and can hide a huge loss.

2. Risking Too Much per Trade

Above 2 percent, a normal losing streak can gut an account. Keep risk small.

3. Moving the Stop to Fit the Size

Set the stop where the trade is wrong, then size to it. Do not widen the stop to justify a bigger position.

4. Ignoring Slippage and Gaps

A stop can fill worse than its price, so your real loss may exceed the planned risk.

5. Forgetting Leverage Limits

If the position value is above your account, you are using margin, which magnifies losses.

The math is exact, but markets do not always respect your stop.

Multiply your account by your risk percent to get the risk amount, then divide by the distance from your entry to your stop-loss. Risking 1 percent of a 10,000 account with a 2 stop distance gives 100 / 2 = 50 shares.

Most traders risk 1 to 2 percent of their account on any single trade. Keeping risk small means a losing streak is survivable, whereas risking large amounts can wipe out an account quickly.

The 1 percent rule means never risking more than 1 percent of your trading account on a single trade. Combined with a stop-loss, it caps the damage any one trade can do.

Yes. For the same risk amount, a tighter stop-loss allows a larger position, because the loss per share is smaller. A wider stop forces a smaller position.

The base calculation does not. If the position value exceeds your account, you would need margin or leverage to take it, which magnifies both gains and losses.

The risk amount is the money you could lose if the stop is hit. The position size is how many shares that translates to, given the distance from your entry to your stop.

No. Place your stop where the trade idea is proven wrong, then size to it. Widening a stop just to buy more defeats the purpose of risk management.

The same risk-based method applies to any market: risk amount divided by the distance to your stop, in the units of that market. Adjust for contract sizes, pip values or lot sizes as needed.

No. The calculation runs entirely in your browser and nothing you enter is stored or sent anywhere unless you choose to Save a result, which stays only in this browser.

• Risk management basics (Corporate Finance Institute).
• Stop-loss orders explained (US SEC Investor.gov).
• Diversification and risk (US SEC Investor.gov).