Free trader tool
Position Size Calculator
Size every trade to your exact risk — across forex, indices, gold and crypto. Enter your balance, risk, entry and stop, and get the precise lot size, dollar risk and reward-to-risk in real time.
- Risk amount
- $100.00
- Stop distance
- 50 points
- Direction
- Long ▲
- Position notional
- ≈ $40,000
- Reward : Risk
- 2 : 1
- Potential reward
- $200.00
You've got your size. Now prove the setup actually works.
Backtest it candle by candle on real market history — free, no card.
Backtest it free →How to calculate position size
Position size comes down to a single question: how many lots — or contracts, or coins — can you hold so that if price hits your stop, you lose exactly the amount you chose to risk, and not a dollar more? Three numbers decide it:
- Risk amount — a fixed percentage of your account (most traders use 0.5–2%) or a set dollar figure.
- Stop distance — how far your stop-loss sits from your entry, in price.
- Point value — what a one-point (or one-pip) move is worth, per lot, on your instrument.
The formula is: Position size = Risk amount ÷ (Stop distance × Point value). The calculator above does the point-value part for each instrument type — pips on forex, points on indices, dollars-per-ounce on gold, straight coins on crypto — so you never have to look up contract specs by hand.
Why position sizing matters
Most blown accounts aren't killed by bad setups — they're killed by good setups sized wrong. Risk 10% on a trade and an ordinary five-loss streak (which every strategy has) roughly halves your account. Risk 1% and that same streak barely leaves a mark. Sizing is the line between surviving variance and getting wiped by it.
Fixing your risk per trade also makes your results readable. When every trade risks the same 1%, your P&L is measured in R — clean multiples you can actually compare, review and improve. Size by gut instead and your equity curve tells you nothing about whether your edge is real.
Lot size calculator: standard, mini and micro
“Lot size” and “position size” are the same number in different clothes. Position size is raw exposure — units, ounces, coins. Lot size is that exposure counted in your broker’s blocks. One standard lot is 100,000 units of the base currency, a mini is 10,000, a micro is 1,000. Get the contract spec wrong and the sizing maths is wrong with it, so here is the lookup:
| Instrument | One unit | Standard | Mini | Micro |
|---|---|---|---|---|
| Forex (USD quote) | 1 pip = 0.0001 | $10.00 | $1.00 | $0.10 |
| Forex (JPY quote) | 1 pip = 0.01 | ~$6.70* | ~$0.67* | ~$0.07* |
| Gold (XAU/USD) | $1 move | $100.00 | $10.00 | $1.00 |
| NAS100 / US30 CFD | 1 point | $1.00† | $0.10† | $0.01† |
| Bitcoin (BTC/USD) | $1 move | $1.00 per coin | — | — |
* JPY pip value moves with the USD/JPY rate — it is not fixed. Shown at roughly 150.00.
† Index point value is broker-specific. CFD desks commonly quote $1 per point per lot; CME futures are $20 (NQ), $50 (ES) and $5 (YM) per point per contract. Check yours before sizing — this single number is the most common source of a position that is 20× too large.
Position sizing by instrument
- Forex — a pip is 0.0001 (0.01 on JPY pairs) and a standard lot is 100,000 units, worth about $10 per pip on USD-quote pairs. USD/JPY’s pip value drifts with the exchange rate; the calculator adjusts for it automatically. If you want the pip figure on its own, the pip value calculator does that job.
- Indices (NAS100, US30, SP500) — quoted in points, and point value is broker-specific. Set your broker’s value in the point-value field rather than trusting a default.
- Gold (XAU/USD) — one lot is 100 troy ounces, so a $1 move is worth $100 per lot. Gold is also where broker lot conventions diverge most: some desks call 0.01 lots a micro, others quote gold in a 10 oz contract entirely.
- Crypto (BTC/USD) — sized directly in coins. A $1 move is $1 per coin, so your position is simply risk ÷ stop distance in dollars.
What each risk level actually costs you
The case for small risk is not caution, it is arithmetic. Losing streaks are not a sign that something has gone wrong — a strategy that wins 50% of the time throws five losses in a row roughly once every thirty trades. What decides whether that is an inconvenience or the end of the account is the number you chose before it started. The right-hand column is the part people miss: a drawdown always costs more to recover than it cost to create.
| Risk per trade | After 5 losses | After 10 losses | Gain needed to recover |
|---|---|---|---|
| 0.5% | 2.5% | 4.9% | 5.1% |
| 1% | 4.9% | 9.6% | 10.6% |
| 2% | 9.6% | 18.3% | 22.4% |
| 5% | 22.6% | 40.1% | 67.0% |
| 10% | 41.0% | 65.1% | 186.4% |
Compounded on the remaining balance, which is how a real account loses money. Recovery figure is from the ten-loss drawdown.
Four ways traders size wrong
- Sizing off leverage. Leverage decides what your broker will permit, never what you should take. Same setup, same stop, same risk — a 1:500 account and a 1:30 account take the identical size.
- Sizing off margin. “I’ll use a quarter of my account’s buying power” is not a risk decision, because it says nothing about where your stop is. A tight stop and a wide stop at the same margin are wildly different risks.
- Ignoring the spread. On a 20-pip stop, a 2-pip spread is 10% more risk than you calculated. On scalps it is the difference between 1% and 1.3% risk on every single trade, compounding all day.
- Moving the stop to fit the size. The stop belongs where the idea is invalidated. If the resulting size feels too small, that is information about the setup, not a reason to move the stop closer.
Sizing is half the job
Correct sizing guarantees you survive a losing streak. It does not tell you whether the setup was worth taking — for that you need a sample, and a sample is the one thing a live account is a slow and expensive way to collect. Work out how many trades you need before the numbers mean anything, then check your plan against the mistakes that make backtest results lie. Once you are taking real trades, what you log decides whether you can ever improve the sizing decision you are making here.
Frequently asked questions
What is a position size calculator?
It tells you exactly how many lots, contracts or units to trade so that if price hits your stop-loss, you lose only the amount you decided to risk. Enter your balance, risk, entry and stop — it returns the size.
How much should I risk per trade?
Most consistent traders risk 0.5–2% of their account per trade. Lower keeps you in the game through losing streaks; higher grows the account faster but sharply raises the odds of a deep drawdown. At 1% risk, ten losses in a row costs about 10% of the account. At 5% it costs 40%, and you now need a 67% gain just to get back to flat.
Does leverage change my position size?
No, and this is the single most common mistake in trading. Leverage decides whether your broker will let you open a position — it has nothing to do with how big that position should be. Size is set by your stop distance and your risk, full stop. A 1:500 account and a 1:30 account trading the same setup with the same stop should take the exact same size.
What is the difference between lot size and position size?
They are the same thing expressed differently. Position size is the raw exposure — units of currency, ounces, coins, contracts. Lot size is that exposure counted in your broker's standard block: 1 standard lot is 100,000 units of the base currency, a mini is 10,000, a micro is 1,000. The calculator gives you both.
Is forex position sizing different from indices, gold or crypto?
The formula is identical — only the point value changes. Forex uses pip value per lot, indices use point value per contract, gold is 100 oz per lot, and crypto is sized directly in coins. This calculator handles each instrument type for you.
Should I include the spread and commission in my stop distance?
Yes, if you want the risk figure to be true. Your stop is hit on the bid or the ask depending on direction, so a 2-pip spread on a 20-pip stop is a real 10% more risk than you calculated. On tight intraday stops it matters a lot; on a 200-pip swing stop it rounds away. Add the spread to your stop distance before sizing, and treat commission as part of the loss.
How do I size a trade if my account is not in US dollars?
Pip and point values are usually quoted in the quote currency, so an account denominated in GBP, EUR or AUD needs one more conversion at the current rate. Size in the quote currency first, then convert the risk figure into your account currency — or set your account currency in the calculator and let it do it. Getting this wrong typically misprices risk by 10–30%, which is enough to matter.
How should I size for a prop firm challenge?
Size against the rule that fails you first, which is almost never the profit target. Most challenges have a daily loss limit and a total drawdown limit; your per-trade risk has to be small enough that a normal losing streak cannot touch either. On a 5% daily limit, risking 1% per trade means five losses in a day ends your session — so most funded traders size at 0.25–0.5% and take the slower path.
Is the calculator free?
Yes — completely free, no signup, no limits. Use it as often as you like.
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