How to Calculate a Stop Loss Price by Percent or Cash Limit

Work from the distance or loss you intend to model

Start with an entry price and a supplied position. The calculator translates either a price move or a cash loss cap into a hypothetical stop and shows how a price grid changes the result.

Distinguish the stop, distance and cash cap

The stop price is a hypothetical exit level on the loss side of entry. A percentage distance measures the move relative to entry. A cash cap includes the stated round-trip charges. The optional price increment sets the spacing of a grid anchored at zero.

Choose the starting constraint

Use percentage mode when comparing equal relative moves from different entry prices. Use cash-cap mode when the loss scenario must include a supplied fee amount.

Calculate the stop and align toward entry

Stop = entry − distance for a long, or entry + distance for a short. In percentage mode, distance is entry times the supplied percentage divided by 100. In cash-cap mode, distance is cap minus charges, divided by quantity. Multiply price distance by shares and add charges to obtain modeled loss. Align a long stop up or a short stop down when an increment is supplied.

Stop = entry − distance for a long, or entry + distance for a short

Check long and short grid outcomes

For 20 long shares at 50, a cash cap of 53 and charges of 4 leave 49 for the price move. The distance is 2.45 and the mathematical stop is 47.55. A 0.10 grid gives 47.60, with modeled loss of 52 and unused cap of 1. The next farther level, 47.50, would cost 54.

For a short with the same inputs, the mathematical stop is 52.45 and 52.40 is the aligned level. Buying back at 52.40 costs 48 more than the opening proceeds for 20 shares. Adding charges gives 52. At 52.50, the modeled loss is 54.

1. Enter 20 shares, entry 50 and charges of 4.
2. Choose cash-cap mode, enter 53 as the cap, and set the increment to 0.10.
3. Compare the mathematical and aligned prices, then switch to short to compare the mirrored example.

Supply prices, quantity and fees

Choose long or short and a calculation mode. Supply the entry, positive share quantity, distance or cap and explicit round-trip charges. Enter zero charges if none apply. Optionally enter the price increment. Switching modes clears the distance or cap field.

Read the loss and unused cap

An aligned level is the farthest grid price that stays within the requested distance and remains on the loss side of entry. If the increment leaves no such price, the mathematical result remains available. Cash headroom is the cap less the modeled loss at the aligned stop.

With entry 50 and a distance of 1%, a grid of 1 gives no long stop strictly between 49.50 and 50. The closest adverse grid price is 49 and exceeds the distance. A grid level at entry represents zero price movement.

Use a hypothetical complete exit

The entire stock position exits once at the shown price. Apply the same stated charges to either mathematical or aligned scenario. Use one major currency throughout. The selected market changes formatting.

Understand the numerical limits and fill uncertainty

Inputs support 12 decimal places. Prices, quantity, cap, charges and increment are bounded by 1 trillion, and the percentage is positive and at most 100. The resulting stop must be positive, strictly adverse and at most 1 trillion. A mathematical price may be rounded to 24 significant digits for display. The grid and modeled losses use unrounded values.

A stop-market order can fill away from its trigger and a stop-limit order can remain unfilled. These cases are outside the two price calculations.

Avoid mixing price distance with account risk

Use the position entry price for the percentage. A price distance of 2% does not imply losing 2% of account equity. Rounding to the nearest grid price can move a stop farther from entry and increase modeled loss.

Keep price and charges in the same units

Use USD, GBP, CAD, AUD or INR for the United States, United Kingdom, Canada, Australia or India. Convert a UK price of 5,000 GBX to £50 before combining it with a GBP charge. ASX documents price steps that vary by price band. The single supplied grid does not infer these schedules.

Choose the matching trading calculation

Risk Per Trade measures loss and equity exposure from an already supplied stop. Position Sizing uses an entry and stop to solve for share quantity. This calculator solves for the stop.

Educational scope

Educational scenario analysis. Actual fills may differ or fail to occur, so realized loss can exceed the modeled loss. The tool excludes broker tick schedules, execution eligibility, borrowing, FX and taxes. It gives no personalized recommendation.

Frequently asked questions

Sources and review

Sources reviewed Nov 11, 2026. Consult current local rules before relying on time-sensitive information.

• Investor.gov stop order bulletin
• CIRO guidance on order types
• London Stock Exchange GBX quote example
• SEBI risk disclosure document
• ASX equities trading