What Lot Size Should I Choose? How to Calculate Lot Size in Forex

This question comes in all the time. Like… all the time.

So let’s just answer it properly once and for all.

The Question:

What Lot Size Should I Choose?

My account balance is $900 and I want to place a trade. I want to risk no more than 1%. Assume a 15 pip stop loss. How big of a lot size should I be trading?

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How to calculate lot size in forex

Step 1: Know Your Numbers

• Account balance = $900

• Risk per trade = 1% = $9

• Stop loss = 15 pips

• Lot size = ???

Step 2: Use the Right Pair (EURUSD = Easy Mode)

Let’s start with EURUSD, because this is where life is simple and we like simple.

On EURUSD:

1 micro lot (0.01) = $0.10 per pip

1 mini lot (0.10) = $1 per pip

Step 3: Work Backwards

You’re risking $9 total.

Your stop loss is 15 pips, so:

9÷15=0.60

That means You can risk $0.60 per pip

Step 4: Convert That to Lot Size

We know: 1 micro lot = $0.10 per pip

So:

0.60 ÷ 0.10 = 6 micro lots

Final Answer

0.06 lot size (6 micro lots)

That gives you:

$0.60 per pip with a 15 pip stop = $9 risk

If Your Account Was $1000 Instead

Same setup, just round numbers:

1% risk = $10

15 pip stop

10 ÷ 15 = 0.66 per pip

0.66÷0.10=6.6 micro lots

You’d trade 0.06–0.07 lots

0.06 = slightly under risk

0.07 = slightly over

(You choose your personality here 😄)

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Why I Start Students on EURUSD

Because this right here is the goal:

You should know your risk before you click anything

You should not be guessing lot size

You should not be doing calculator gymnastics mid-trade like a stressed-out accountant

EURUSD lets you focus on the trade, not the math.

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Quick Rule You Can Remember

If you’re trading EURUSD: Lot size = (Risk ÷ Stop Loss) ÷ 0.10

Or even simpler: $1 per pip = 0.10 lot

So just scale up or down from there.

Bottom Line

👉 Account → Risk → Stop Loss → Lot Size

In that order. Every time.

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LOT SIZE CHEAT SHEET (EURUSD)

Base Rules (burn these into your brain):

1 micro lot (0.01) = $0.10 per pip

1 mini lot (0.10) = $1 per pip

💰 Step 1: Know Your Risk

Account	1% Risk
$500	$5
$900	$9
$1000	$10
$2000	$20

📉 Step 2: Match Stop Loss to Lot Size

15 Pip Stop

Risk	$/Pip	Lot Size
$5	$0.33	0.03
$9	$0.60	0.06
$10	$0.66	0.06–0.07
$20	$1.33	0.13

20 Pip Stop

Risk	$/Pip	Lot Size
$5	$0.25	0.02–0.03
$9	$0.45	0.04–0.05
$10	$0.50	0.05
$20	$1.00	0.10

The Only Formula You Need

Lot Size = (Risk ÷ Stop Loss) ÷ 0.10

Or even simpler:

Risk ÷ Stop = $ per pip → convert to lot size

What People Do Wrong

Pick lot size first

Then figure out risk

Then pray

What You Do Now

Set risk

Set stop

Calculate lot size

Then place the trade

If you know your risk and your stop before you ever touch the buy or sell button, your lot size isn’t a guess anymore — it’s just math, and that’s what keeps you in the game.

Now you know What Lot Size Should I Choose? and How to Calculate Lot Size in Forex.