Position Size Calculator

Position Size Calculator is a free browser-based tool that helps you calculate optimal position size based on risk. It is part of ToolsMonk's stock market tools collection, so you can finish the job without downloading software, creating an account, or jumping between multiple websites.

This tool is especially useful for workflows such as sizing a trade so a stop-loss risks a fixed % of your account, enforcing consistent risk across trades, and avoiding oversized positions that risk too much. Because it runs directly in your browser, you can use it on desktop, tablet, or mobile while keeping the process fast and easy for one-off tasks as well as repeat work.

Position Size Calculator is designed for people who want a practical, privacy-friendly workflow with instant results inside the larger ToolsMonk library.

Position Size Calculator works out how many units to trade so that hitting your stop-loss costs only a fixed, pre-decided amount — from your account size, risk percentage, entry, and stop. It's the backbone of disciplined risk management.

The formula divides the money you're willing to risk (account × risk %) by the per-unit risk (entry-to-stop distance), giving a size that caps your loss at exactly your intended amount. That translation of a stop in price terms into a concrete position size is what most traders skip — and what most account blow-ups come from.

Why it matters more than analysis: proper sizing ensures no single trade can do serious damage, keeping you solvent long enough for your edge to play out. The widely-recommended principle is to risk a small, consistent slice — often 1–2% — per trade, because oversizing accelerates drawdowns and ends accounts.

Sizing controls losses, not wins: it makes losing streaks survivable rather than fatal, but it doesn't create profit. It's an analysis aid, not trading advice, and runs entirely in your browser. Pair it with the Risk-Reward and Lot Size calculators for complete trade planning.