How to use the calculators

The above calculators will help you to size long and short positions. The operation itself is simple algebra but it's tedious so I wrote this page to speed things up.

Definitions:

Maximum Cost: How much money you have (i.e. 1000). All this does is puts an upper limit on how many shares you buy/sell. Make this some reasonable percentage of your account size like 10%. Remember, it's bad to bet all your money on one trade.

Risk: How much money you are willing to lose in dollars (or a percentage of Maximum Cost in the case of %Risk)

Buy/Sell Price: The price you'll be buying (or short selling) the position at (i.e. 14.11).

Stop Price: Where your stop point is.

Position Type: What type of position this is (i.e. Long or Short).

Shares to Buy/Sell: How many shares you should buy or sell based on the information you've entered. The calculators will fill this in for you.

The Static Position Size calculator basically answers the question: If I have x dollars to spend and I'm willing to lose up to y amount, how many shares should I buy (or sell) and where should I put my stop? The red asterisks denote required fields.

The Dynamic Position Size calculator is a little smarter and (in my opinion) better. It tries to answer the question: How many shares of a stock should I buy (or sell) if I'm willing to lose up to x amount and the price changes from y to z? The red asterisks denote required fields.

If you're hitting the GO! buttons and nothing's happening then you've probably left one of the required fields blank or entered an invalid character (don't include dollar signs, commas, percents, etc).

Important: I make no guarantees for the accuracy of the calculators. They work for me but you should check the results yourself before you put your money on the line. If you use the calculators, invest a bunch of money based on the results, and then subsequently lose all that money then... well... that's a bummer. Know the risks before you start!

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