Lot size calculator
How big should the trade be? Enter your balance, how much you are willing to lose and where the stop loss sits. You get the lot size, what one point is worth, the margin it locks and what a losing streak would do to the account. Gold, forex and indices. New to the words? The glossary explains each one.
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How the calculation works
The idea is simple: decide how much money you are willing to lose on the trade, work out how much one lot would lose if the stop loss is hit, and divide one by the other.
The value of one point comes from the instrument's contract size and point size, converted into your account currency. That is why the same risk gives different lot sizes on gold, EURUSD and indices, and slightly different ones between brokers. The result is then rounded down to your broker's lot step, so you never risk more than you asked for, unless even the minimum lot is too big.
A worked example on gold
- Balance $1,000, risk 1%: you are willing to lose $10.
- Stop loss 1,000 points away. On gold that is a $10 move in the price.
- 1.00 lot of gold is 100 ounces, so a $10 move costs $1,000 per lot.
- $10 ÷ $1,000 = 0.01 lot, which is also the smallest trade most brokers allow.
Double the stop distance and the right size would be 0.005 lot, which doesn't exist. At 0.01 lot you would be risking 2%. This is why very small accounts can't always follow their risk setting on gold.
Questions
What lot size should I use on a $1,000 account trading gold?
It depends on your stop loss. At 1% risk ($10) and a stop 1,000 points away ($10 in the gold price), the answer is 0.01 lot, the smallest size most brokers allow. With a wider stop, even 0.01 lot risks more than 1%, so the calculator will warn you.
What risk per trade should a beginner use?
Most beginners are safer at 0.5% to 1% of the account per trade. At 1%, ten losses in a row, which every strategy will eventually have, cost about 10%. At 5%, the same streak costs around 40%.
Does higher leverage mean more risk?
Not by itself. Your risk per trade is set by the lot size and the stop loss distance. Leverage only decides how much margin is locked while the trade is open. High leverage becomes dangerous when it lets you open lots that are far too big for the account.
Why does my EA use a slightly different lot than this calculator?
An EA reads your broker's exact tick value, lot step and current equity at the moment it trades, and the stop distance changes from trade to trade. Small differences are normal. A big difference usually means a different risk setting or a symbol with a different contract size.
Know your size. Now test it.
Run a free EA on a demo account with the risk you calculated here, and watch how the numbers behave before any real money is involved.