How to calculate position size
Divide the value of a position by the value of the whole portfolio and multiply by 100. Use the same currency and valuation date for both amounts.
If a position is worth $7,500 and the total portfolio is worth $150,000, its weight is 7,500 ÷ 150,000 × 100 = 5%. The portfolio total must already include the position.
Compare different position amounts
For a hypothetical $100,000 portfolio, these position values produce the following weights. The calculation describes an allocation; it does not recommend one.
| Position value | Portfolio value | Position weight |
|---|---|---|
| $2,000 | $100,000 | 2% |
| $5,000 | $100,000 | 5% |
| $10,000 | $100,000 | 10% |
| $25,000 | $100,000 | 25% |
Position weight is only one part of risk
A position’s weight shows how much of the portfolio it occupies. It does not show how volatile the asset is, whether it can be sold quickly, or whether other holdings are exposed to the same underlying risk.
A larger position amplifies the effect of that position’s gains and losses on the whole portfolio. Overlapping holdings can also create concentration. FINRA explains how concentration risk can arise.
Frequently asked questions
Should cash be included in total portfolio value?
Include cash if it is part of the portfolio you are measuring. Define the portfolio consistently and include each asset only once.
Is this a trading position sizing calculator?
It calculates portfolio allocation by value. It does not calculate shares from an entry price and stop-loss, and it does not assume a stop order limits your losses.
What position size should I choose?
The calculation cannot choose an appropriate allocation for you. Your goals, financial circumstances, asset risks, and other holdings all matter.
Published by investor.wtf. Read the formulas, assumptions, and how these pages are made.