Forex Position Size Calculator
Know your exact lot size before you click buy. Any pair, any account currency - sized to the risk you actually chose.
If your stop moves
You sized this at 1.0% risk. Do you hold that line on every trade?
Connect your account and Helix AI flags every trade where you sized past your own rule - automatically, on your real fills.
Check my real risk disciplineHow position sizing works
Position sizing answers one question: how big can this trade be so that if the stop gets hit, you lose only what you planned to lose. Three numbers decide it - your account balance, the percentage of it you are willing to risk, and the distance to your stop loss. Everything else the calculator shows (units, margin, reward) is derived from those three.
The order matters. Most losing traders pick a size first and hope the stop works out; disciplined traders pick the risk first and let the size fall out of the math. Sizing this way makes every trade cost the same when it fails, which is what keeps one bad day from undoing a good month.
Worked example: EURUSD
Say your account is $10,000 and you risk 1% per trade - a $100 budget. Your setup on EURUSD needs a 25 pip stop. One standard lot of EURUSD moves $10 per pip, so 25 pips costs $250 per lot. Your size is 100 / 250 = 0.40 lots. If the stop is hit you lose $100, exactly the budget - not a dollar more because the size was derived from it.
Worked example: gold
Gold trades in 100 oz lots, so each $0.01 move is $1 per lot. With the same $100 budget and a $2.50 stop (250 points at $0.01), one lot risks $250 - your size is 0.40 lots again. Different market, different contract, same discipline. The calculator carries the contract specs for every market it lists, so you never have to remember them.
Pips, points and the JPY convention
For most currency pairs a pip is 0.0001. For yen pairs it is 0.01, which makes one pip worth 1,000 yen per standard lot - and that yen value has to be converted to your account currency at the live rate, not a fixed guess. This is where many free calculators quietly drift; this one converts at the latest market rate every time, and lets you override any rate manually.
Account currency, handled properly
A EUR account trading GBPJPY involves three currencies: your balance in euros, a stop distance priced in yen, and a position in pounds. The calculator converts your risk budget and the pip value through the latest rates so the number you see is the number you would actually lose. When a rate is missing you can type it in - the tool never guesses.