Work out profit or loss from cost and selling price, or find the price you need for a target percentage.
With Cost price = 500, Selling price = 650:
Profit % = (selling price - cost price) / cost price x 100. Example from the worked example above: cost Rs 500, selling Rs 650 gives a Rs 150 profit, which is 30%.
Loss % = (cost price - selling price) / cost price x 100.
Yes - pick what you want to find (selling price, cost price or percentage) and fill in the values you know.