Stop Loss Calculator

How the calculator works

A stop loss is an order that closes a position once price reaches a set level, so that a losing trade ends at a known place. This calculator takes the stop as a percent distance from the entry, because that is how many people think about it, and turns it into a price and a dollar loss.

A worked example

Take a made-up $10,000 account and a long position of 50 units entered at $100, with a stop 5 percent away. The stop price is 100 x 0.95 = $95. The loss if it fills there is 50 x $5 = $250, which is 2.5 percent of the account. The size that would make the loss exactly 1 percent is $100 / $5 = 20 units. Calculated by us on 27 Oct 2026, exact arithmetic on made-up inputs.

A short position with the same settings has its stop at $105 and the same $250 loss. The only change is the direction price must move to hit it.

Three common kinds of stop

These are descriptions of how people set the distance, not recommendations. Each has costs.

• Fixed percent. The stop sits a set percent from entry, as in this calculator. It is easy to compute and ignores how much the market normally moves, so in a quiet market it can be too wide and in a busy one too tight.
• Volatility. The distance is a multiple of a measure of recent price range, for example the average true range. It adapts to the market, but the multiple is still a choice, and a sudden change in range can break it.
• Structure. The stop goes beyond a chosen price level, such as a recent low. It ties the exit to the idea behind the trade, but the distance varies and may be large, which then forces a smaller size.

Where gaps and bots break the stop

Gaps and slippage

A stop does not fix the price you get. When price jumps past the stop between trades, for example over a weekend, or moves faster than orders can be filled, the order fills at the next available price. Suppose the made-up position above gaps from $100 straight to $91. The stop at $95 triggers, but the fill is at $91, so the loss is 50 x $9 = $450, or 4.5 percent of the account, not $250. That is 1.8 times the planned loss. Some products offer stops that fill at the set price for a fee, and many do not, so check what yours does. The guide to slippage covers the size of the gap in more detail.

A stop on the whole stack

Grid and martingale bots often have a single stop for the entire set of orders, rather than one per entry. That changes the maths. Take three made-up buys of 10, 20 and 40 units at $100, $95 and $90. The average entry is 6,500 / 70 = $92.86, and a stop at $85 closes 70 units, a loss of 70 x 7.86 = $550. The stop on the last order alone would have been 40 x $5 = $200. The stop price is at the same level, but the loss is much larger because the position grew on the way down.

Some bots have no stop at all and rely on price coming back. For those the loss at the stop is not defined, which is why position sizing from a stop does not apply to them.