ExecutionRisk Control

Position Size Calculator

Size CSE positions using portfolio risk, stop-loss distance, execution friction, and optional reward-to-risk targets for more disciplined trade construction.

Risk-based share sizingTarget reward-to-riskConcentration and liquidity controls

Trade sizing assumptions

Position size starts with a risk budget. Advanced mode then adds execution friction and concentration controls.

Portfolio size

LKR

Risk per trade

Entry price

LKR

Stop-loss distance

Advanced mode

Add fees, slippage, target reward, and a cap on maximum portfolio concentration.

Stop-loss price

LKR 50.60

The stop-loss defines the per-share downside that your risk budget is absorbing.

Risk budget

LKR 10,000.00

Max shares

2,272

Position value

LKR 124,960.00

Portfolio concentration

25.0%

Scenario view

How stop width changes the trade

A tight stop gives you more shares. A wider stop gives the trade more room, but it reduces size.

Stop distance	Stop price	Max shares	Position value	Concentration
5%	LKR 52.25	3,636	LKR 199,980.00	40.0%
8%	LKR 50.60	2,272	LKR 124,960.00	25.0%
10%	LKR 49.50	1,818	LKR 99,990.00	20.0%
12%	LKR 48.40	1,515	LKR 83,325.00	16.7%

Interpretation

Reading the output

The calculator sizes the trade from the amount you are willing to lose, not from the amount you hope to make.

With an entry at LKR 55.00 and a stop at LKR 50.60, each share carries about LKR 4.40 of modeled downside once execution friction is included. A LKR 10,000.00 risk budget therefore supports roughly 2,272 shares, or LKR 124,960.00 of capital.

Perspective

Position sizing becomes much more useful when friction is visible

Basic position sizing assumes a perfect fill and a clean stop-loss execution. Real-world trading usually involves some slippage, commissions, and concentration limits that change the true position you should take.

Adding a target-price field also lets you judge whether the setup offers enough upside relative to the risk budget you are consuming.

This is why advanced mode adds execution friction and concentration controls instead of only returning a single share count with no context.

Read the glossary: stop-loss

FAQ

Common questions

Why is stop-loss distance central to position size?

Because risk per share is defined by the gap between your entry and stop-loss level. The wider that gap, the fewer shares you can buy for the same overall rupee risk budget.

What does reward-to-risk mean?

Reward-to-risk compares the upside to your target price with the downside to your stop-loss. Many traders prefer setups where the potential reward is meaningfully larger than the potential loss.

Why cap position size as a percent of portfolio?

Because risk-based sizing can still suggest a very large allocation if the stop-loss is tight. A concentration cap prevents any single position from becoming too dominant.

Keep the workflow moving

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Cost Basis