what is the smallest lot size i can trade in forex

0.01 is the smallest lot size that your broker will probably allow you to trade. This means when entering lot size you can enter sizes such as: 0.01, 0.02,0.03, 0.04, 0.05 etc. in that sequence.

Remember that the smaller the lot size, the smaller your potential profit/loss. If you decide to trade larger lot sizes than 0.01, then you risk larger losses if the trade doesn't go as planned.

To resist the temptation to trade bigger lot sizes, you can open a micro account where you lot size is restricted to 0.01 only.

The smallest volume of an currency pair you can trade in forex is 0.01 lot size. The order entry box will not even let you enter any value below 0.01. Beginners may want to stick to trading 0.01 lot size till they become consistently profitable then they can scale to bigger lot sizes.