There is a FREE trade manager tool below that will do this for you, but YOU MUST be able to understand this and do it manually. You always want to know what you are risking (would you go shopping and make purchases without knowing the cost?

1) Per Trade Risk - It' good practice to only risk 0.25% to 3% of your overall account size per trade. If you plan to execute multiple trades per day then reduce the risk % per trade to ensure you do not go over your daily maximum risk)

2) Maximum Daily Risk - Set a maximum risk per day (1% to 3% is widely used)

3) How to Calculate your Risk

Balance X Risk % e.g £1000 x 0.01 (1% risk) = £10 (Risk £10.00 per Trade)

4) Calculate Your Stop Loss Pip Total

5) Use a Pip Value Calculator to determine your Lot Size (Risk £ per pip)

I use this Pip Value Calculator