Risk Budget
——ACCOUNT & RISK MANAGEMENT
Position Size Calculator
Calculate theoretical position size from account equity,
risk per trade, entry price, and stop-loss price.
See estimated quantity, notional exposure, and theoretical margin requirements
without using leverage to determine your risk budget.
01 / Trade setup
Risk budget and prices
Enter the assumptions for a single trade.
02 / Results
Theoretical position
Results will reappear once the inputs are valid.
Position Quantity
——Position Notional
——Account Exposure
——Risk Breakdown · Loss per unit
- Stop distance
- —
- Price loss per unit
- —
- Entry cost per unit
- —
- Stop exit cost per unit
- —
- Estimated costs per unit
- —
- Total estimated loss per unit
- —
Position quantity = risk budget ÷ total estimated loss per unit
Margin Comparison
Leverage doesn't change your risk budget. It only changes how much margin the same notional position requires.
| Leverage | Required Margin | Share of Equity |
|---|
Exchange maintenance margin and liquidation rules are not included. This table does not suggest any leverage level.
Reading the numbers
What these results mean
These are educational estimates based on your assumptions, not a suggestion to buy or sell any quantity.
Risk per trade is an input assumption, not a recommendation.
MoneyWorkLab
More risk tools are being added to MoneyWorkLab.
This calculator is part of a set of account and risk management tools. Additional English tools will be listed here once they're available.
Position sizing guide
What to settle before you size a trade
Eight short explainers to help you read the results.
What is position sizing?
Position sizing is deciding how many shares, coins, or contracts to trade. Instead of starting with how much you want to make, this calculator starts with how much of your account you're willing to lose if the trade hits your stop.
Divide that dollar risk by the estimated loss on one unit, and you get a theoretical quantity. Same account, same risk budget, different stop — and the quantity can change a lot.
Risk per trade vs. position value
Risking 1% of a $10,000 account doesn't mean buying $100 worth of something. It means that if your stop is hit, you expect to lose about $100. With the default inputs, that $100 risk supports a position worth roughly $3,187.
Mixing up these two numbers is one of the most common sizing mistakes. The risk budget caps your loss; the notional value is how much market exposure you actually hold.
Why stop-loss distance matters
Your stop distance sets how much one unit can lose. Enter at $100 with a stop at $97 and each unit can lose $3 before costs, so a $100 risk budget covers about 33 units.
Move the stop to $99 and each unit only risks $1, so the same budget covers about three times as many units. A tighter stop doesn't reduce your dollar risk — it increases your size.
Does leverage change risk per trade?
Not in this calculator. Quantity comes from your risk budget and stop distance only; leverage is never an input to that step. Picking a leverage first and sizing up to match it is how losses end up larger than planned.
The margin table takes the position you've already sized and shows how much margin it would tie up at 1x through 10x. Higher leverage lowers the margin, but your loss at the stop stays the same — and your liquidation price can move closer to your entry.
Fees and slippage
The calculator charges fee + slippage once when you enter and once when the stop fills. With the defaults, that adds about $0.14 to the $3 price loss, for an estimated $3.14 per unit.
A bigger loss per unit means a smaller quantity for the same budget. The tighter your stop, the larger the share of each unit's loss that comes from costs.
Long vs. short position sizing
A long loses money when price falls, so the stop must be below entry. A short loses when price rises, so the stop must be above entry. The calculator won't run if the stop is on the wrong side.
With the same stop distance, a short's stop sits at a higher price, so its exit cost is slightly higher and the quantity comes out slightly smaller than an equivalent long.
Gap and execution risk
A stop-loss order isn't a guaranteed price. Earnings releases, overnight news, trading halts, and fast markets can push price straight through your stop, filling you at a worse level. In thin markets, your own order can move the price.
When that happens, your actual loss can be larger than the risk budget shown here. Results assume your stop fills at the price you entered.
Calculator limitations
Costs are simplified to a fixed percentage at entry and at the stop. Variable slippage, maker/taker fee differences, funding rates, borrow fees, maintenance margin, liquidation, taxes, gap risk, and partial fills are not modeled.
Lot sizes, minimum order sizes, and tick sizes aren't applied either, so you may see fractional quantities. All results are educational estimates, not trading advice.
FAQ
Frequently asked questions
What is a position size calculator?
It's a tool that works backward from your risk. You set how much you're willing to lose on a trade, enter your entry and stop-loss prices, and it estimates how many units you can hold so that a stop-out costs about that amount, including estimated fees and slippage.
What does risk per trade mean?
It's the share of your account you expect to lose if a trade hits its stop. At 1% on a $10,000 account, a stopped-out trade should cost roughly $100. The percentage is your own assumption; this calculator doesn't set it for you.
Is position size the same as account risk?
No. Account risk is the dollar amount you could lose at the stop. Position size is how many units you hold, and notional value is quantity × entry price. With the defaults, the risk is $100, the quantity is about 31.87 units, and the notional value is about $3,187.
Does leverage change my risk budget?
No. Your risk budget and stop distance set the quantity. Leverage only changes the margin needed to hold that same position, which is what the 1x–10x table shows. Maintenance margin and liquidation are not calculated.
Why does a tighter stop increase position quantity?
Each unit can lose less before the stop is hit, so the same dollar risk covers more units. That also means a bigger notional position — a very tight stop can produce a position larger than your whole account.
Are fees and slippage included?
Yes, as a simple estimate. Enter them per side, and the calculator applies fee + slippage at the entry price and again at the stop price. Leaving them at zero makes the quantity larger and your real loss at the stop more likely to exceed your budget.
Can I use this for stocks and crypto?
Yes. The math only uses prices and quantities, so it works for stocks, ETFs, crypto, and other instruments. It handles prices below $1 and fractional quantities, but it doesn't apply lot sizes, tick sizes, minimum orders, or taxes.
Does it work for short positions?
Yes. Choose Short and enter a stop-loss price above your entry. Short-specific costs such as borrow fees, funding, and dividends owed are not included.
Does this calculate liquidation price?
No. Liquidation prices depend on the exchange, the product, maintenance margin rates, and whether you use cross or isolated margin. The margin table is simply notional value divided by leverage.
Can actual loss exceed the calculated risk amount?
Yes. Price gaps, fast-market slippage, partial fills, and rounding to whole units can all make your real loss different from the estimate — sometimes larger. The results assume your stop fills at the price you entered.
Before you use the numbers
What the cost model includes — and what it doesn't
This is an educational calculator that shows how position sizing works.
It is not investment advice or a suggested trade size, and results aren't guaranteed.
Included
Not included
Costs are estimated as (per-side fee + per-side slippage) applied once at the entry price and once at the stop-loss price. Currency selection only changes display formatting; no FX conversion is performed.