Position Size Calculator ATR
- Indicators
-
Prime Horizon
🎯 MT5 Developer — Market Structure, Smart Money & Funded Trading Tools
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ - Version: 2.0
- Updated: 28 May 2026
Position Size Calculator Lite MT5 - Free Risk Management Indicator (v2.0)
Free Lite version of the Position Size Calculator. If you need interactive drag and drop of SL/TP lines, Fixed Lot mode and adjustable Risk/R:R/ATR from the panel, see the PRO version on the Market: Position Size Calculator PRO MT5.
Overview
Position Size Calculator Lite MT5 is a free indicator that calculates the recommended lot size for a trade based on a risk percentage, an ATR-based Stop Loss and a target risk/reward ratio.
No trading operations: this indicator does not open or close orders and does not manage positions. It is a decision-support tool before manually placing your trade in MT5.
New in v2.0 - UI refresh
- New MSOB-style dashboard: glow header, central LOT, 3D Entry/SL/TP cells, result bar (Risk, R:R), footer
- Header draggable by click and hold to position the panel anywhere on the chart
- Filled SL/TP zones (red/green) extending from the current candle
- Faint dotted Entry/SL/TP extensions to the past for a cleaner chart
- Clear BUY/SELL toggle showing the next action (BUY > SELL / SELL > BUY)
- Automatic DPI detection for high-resolution screens
What you see on the chart
- Recommended lot size based on risk and SL distance
- Entry, Stop Loss, Take Profit with distances in pips
- Estimated risk (account currency and %)
- Risk/Reward ratio
- BUY or SELL direction with one-click toggle
Calculation method
- Read account balance and compute the risk amount via RiskPercent
- Define entry price based on direction (Ask for BUY, Bid for SELL)
- Compute Stop Loss distance: ATR multiplied by ATR_Multiplier
- Project Take Profit using TargetRR
- Compute lot size so the loss at SL matches the risk amount, respecting symbol constraints (tick value, tick size, volume min/max/step)
Lite limitations and PRO features
This Lite version is intentionally limited. The following features are available in the PRO version:
- Interactive drag and drop of SL/TP lines on the chart
- Automatic direction flip when crossing the entry line (BUY/SELL)
- Fixed Lot mode with AUTO/FIX toggle
- Adjustable Risk, R:R and ATR Multiplier from the panel
- Compact mode and customizable DPI scaling
- Real-time Spread and ATR displayed
- Required margin shown in the panel
Main parameters
- DefaultDirectionBuy: direction on load (true=BUY)
- RiskPercent: risk per trade in %
- TargetRR: target risk/reward ratio
- ATR_Multiplier: ATR multiplier for SL distance
- ATR_Period: ATR period
- ShowChartLines: show Entry/SL/TP lines
- ShowPanel: show the panel
- PanelX, PanelY: initial panel position
Markets and timeframes
- Forex, indices, CFDs, commodities, crypto (depending on the broker)
- Works on any MT5 timeframe
How to use
- Add the indicator to a chart
- Set RiskPercent, TargetRR and ATR_Multiplier in the inputs
- Choose direction with the BUY > SELL button
- Use the displayed lot size to place your order manually in MT5
Update history
v2.0 - Major UI refresh: new MSOB-style dashboard, header drag, filled SL/TP zones, dotted leftward lines, clarified BUY/SELL toggle, automatic DPI detection
v1.1 - Added BUY/SELL toggle button, optional Entry/SL/TP lines, line customization parameters
Disclaimer
This indicator is intended for educational and decision-support purposes only. Trading involves a risk of capital loss. Always test on a demo account and apply appropriate risk management.
Your feedback helps other traders discover this tool. Feel free to leave a rating if the indicator is useful to you.
