Profit Threshold calculates the point at which your trade will begin to make a profit after trading fees have been taken into consideration.
If you have bought bitcoins (going long) the threshold will be the point that selling all your bitcoins will give you a profit in fiat (USD).
If you have sold bitcoins (shorting) the threshold will be the point where buying bitcoins will give you more bitcoins then you started the trade with.
Profits or Losses calculates the amount of profit or loss the pair of trades will make you. It gives you a fiat figure (USD) if you are going long and a bitcoin figure if you are shorting.
USD ($) is only used for illustration, obviously the calculator will work with any currency just be consistant with what you enter.
Please note that the easy Bitcoin Trading Calculator is to be used for guidance only. It is only accurate to 8 significant figures.
Remember folks - Buy low and Sell high.