A position size calculator built around your stop-loss
Position sizing answers the most important question in a trade before you place it: how much? This position size calculator works backwards from the amount you are willing to lose. Enter your account size, the risk per trade (say 1% of the account, or a fixed ₹5,000 or $200), your entry price and your stop-loss, and it tells you how many shares, futures lots, forex lots or crypto units to buy so that a stop-out costs exactly that amount and no more.
It handles four markets with their own units: whole (or fractional) shares for stocks in India, the US or the UK; exchange lot sizes for futures and options; standard, mini and micro lots with pip values in your account currency for forex and gold; and fine quantity steps plus leverage for crypto. It also shows the position value, the share of your account it uses, reward-to-risk at your target, margin, and a table of sizes at 0.5% to 5% risk.
How to use the Position Size Calculator
- Choose the market — Stocks, Futures & options, Forex or Crypto — and your account currency.
- Enter the account size and the risk per trade, as a percentage of the account or as a fixed amount.
- Enter the entry price and the stop-loss price (for forex, the stop distance in pips). A stop below the entry means a long trade; above it, a short.
- Add the market details: the exchange lot size for futures; pip size, contract size and how your account currency relates to the pair for forex; the quantity step for crypto.
- Optionally enter a target price to see reward-to-risk and the profit at the target, and a leverage or margin figure.
- Read the size, check the worked steps and the risk ladder, and copy the result into your trading journal.
Position Size Calculator features
Four markets, correct units
Shares, exchange lots, forex lots in 0.01 steps, and crypto quantity steps — always rounded down so the loss never exceeds your limit.
Risk as % or amount
The classic 1% or 2% rule, or a fixed rupee, dollar or pound figure.
Forex pip values
Pip value of a lot in your account currency for quote-currency, base-currency and cross accounts.
Reward:risk and margin
Profit at the target, the ratio to your risk, futures margin per lot or leverage-based margin.
Risk ladder
The size at 0.5%, 1%, 2%, 3% and 5% risk side by side.
The position sizing formula
Money at risk = account × risk %, then size = money at risk ÷ risk per unit, where the risk per unit is the distance from entry to stop for one share, one futures lot (distance × lot size) or one forex lot (stop in pips × pip value of a lot). The answer is always rounded down, because rounding up would break the rule you set.
Worked example (stocks, India): account ₹5,00,000, risk 1% = ₹5,000. Buy at ₹1,250 with a stop at ₹1,220: the risk is ₹30 a share, so ₹5,000 ÷ ₹30 = 166.7 → 166 shares. If the stop is hit you lose ₹4,980 before charges. The position costs ₹2,07,500 — 41.5% of the account — and with a target of ₹1,310 the reward is ₹60 a share, a 2 : 1 reward-to-risk.
Futures: with a lot of 75 units, buying at 24,000 with a stop at 23,900 risks 100 × 75 = ₹7,500 a lot. A ₹5,000 risk budget allows zero lots — the honest answer is that the trade is too big for the account at that stop. At 2% (₹10,000) one lot fits.
Forex lots and pip values
A standard forex lot is 100,000 units of the base currency, a mini lot 10,000 and a micro lot 1,000. For most pairs a pip is 0.0001; for yen pairs it is 0.01. The pip value of one standard lot is pip × 100,000 in the quote currency: $10 for EUR/USD, ¥1,000 for USD/JPY. If your account is in the base currency, divide by the price (¥1,000 ÷ 150 = $6.67); for any other account currency, multiply by the rate you enter.
Example: a $10,000 account risking 1% ($100) with a 25-pip stop on EUR/USD risks $250 a standard lot, so the size is 0.40 lots. For pip values, margin and lot sizes on their own, use the forex pip value and lot size calculator.
Tips and limits
- A stop-loss is an order, not a guarantee: overnight gaps and fast markets can fill it lower, so the real loss can exceed the planned risk.
- Charges are not included. Check the full cost of a share trade with the stock profit calculator.
- Futures lot sizes and margins are set by the exchange and broker and are revised from time to time — enter the current figures.
- Indian residents may trade forex only through authorised persons on recognised Indian exchanges or RBI-authorised platforms; offshore leveraged forex sites are not permitted.
Position Size Calculator FAQ
How do I calculate position size?
Decide the money you will risk (for example 1% of the account), measure the distance from your entry to your stop-loss, and divide: size = risk amount ÷ (entry − stop). The position size calculator does this for shares, lots and coins, and rounds down.
What is the 1% rule in trading?
Never lose more than 1% of your trading account on a single trade. On a ₹5,00,000 account that is ₹5,000; on $10,000 it is $100. It is a rule of thumb, not a requirement — the calculator lets you choose any percentage or a fixed amount.
How do I use a position size calculator for forex?
Choose Forex, enter the account, the risk and the stop in pips, the pip size (0.0001, or 0.01 for yen pairs) and the contract size. Tell it whether your account currency is the pair’s quote or base currency, or enter a conversion rate, and it returns lots in 0.01 steps.
Is there a position size calculator for India?
Yes — this one works in rupees with Indian digit grouping (₹5,00,000) and handles NSE/BSE equity shares and F&O lots. Enter the exchange’s current lot size for the contract.
Does position size depend on the target?
No. Size depends only on the risk amount and the stop distance. The target only changes the reward-to-risk ratio and the potential profit.
Why is the answer zero?
Because even the smallest tradable size would lose more than you allowed. Use a tighter stop, a smaller instrument, a higher risk budget or skip the trade.