MT5 Add-in
MT5 Lot Size Calculator EA
One click. Correct lot size. Every trade. Across every asset class on MetaTrader 5.
Why a built-in calculator beats every alternative
Most retail MT5 traders calculate lot size three ways: a fixed number (0.1 lots regardless of stop distance), mental math under pressure, or an external calculator that breaks their workflow. All three lead to inconsistent risk per trade — and inconsistent risk is what blows accounts.
Rical attaches to your chart as an Expert Advisor. As you move your stop-loss line, the lot size updates in real time based on your account balance, your chosen risk percentage, and the actual pip value of the instrument you're trading. When you click BUY or SELL, the trade is placed at the correct size automatically.
Lot size formula Rical uses (so you know it's right)
lots = (account_balance × risk_percent) / (sl_distance × pip_value_per_lot)
For a £10,000 account, 1% risk, 30-pip stop on EURUSD with £8/pip-per-lot value:lots = (10,000 × 0.01) / (30 × 8) = 0.42 lots
The formula is the same on every instrument. What changes is thepip_value_per_lot— and that's the part most retail traders get wrong. Rical pulls the live tick value from your broker, so XAUUSD, GBPJPY, US30, BTC/USD and EURUSD all calculate correctly without you doing the math.
Free vs. Rical
| Feature | Free script / web calc | Rical (£25) |
|---|---|---|
| Live lot size as you move SL | ❌ | ✅ |
| One-click trade entry at sized lot | ❌ | ✅ |
| Works on XAU, indices, crypto CFDs | Partial | ✅ |
| Reads account balance live from MT5 | ❌ | ✅ |
| No tab switching mid-setup | ❌ | ✅ |
| Stays on chart between sessions | ❌ | ✅ |
| Updates as you change risk % | ❌ | ✅ |
Works on every instrument
Rical handles instruments where retail traders most commonly mess up sizing:
- ✓ FX majors (EURUSD, GBPUSD, USDJPY, etc.)
- ✓ JPY crosses (GBPJPY, EURJPY) — pip value shifts daily, Rical handles it
- ✓ Metals: XAUUSD (gold), XAGUSD (silver) — "pip" ≠ pip, Rical knows
- ✓ Indices CFDs: US30, NAS100, GER40, UK100 — point-based, Rical adjusts
- ✓ Crypto CFDs: BTCUSD, ETHUSD — non-standard pip math, handled
- ✓ Any account base currency (GBP, USD, EUR, AUD, etc.)
Frequently asked
Does Rical work on XAUUSD and JPY pairs?
Yes. Rical handles non-FX-major pip math correctly — gold, silver, JPY crosses, indices CFDs and crypto CFDs all calculate properly using the broker's reported tick value.
Does it work with prop firm accounts?
Yes. Rical reads your account balance and currency directly from MT5, so it works identically on prop firm accounts, demo accounts and live retail accounts.
Is there a subscription?
No. Rical is £25 one-time. You receive the compiled .ex5 file by email after purchase and own it for life on the broker accounts you install it to.
How is this different from a free MT5 lot size calculator?
Most free options are scripts that calculate once and don't update. Rical is an EA that runs continuously on your chart, recalculates as you move the SL line, and lets you place the trade with one click at the correct size.
Stop sizing trades by feel.
£25 one-time. Compatible with MetaTrader 5. Instant email delivery.
Get Rical — £25Looking for context first? Read our deep-dive on MT5 position sizing, or grab the free risk-management guide.