Profit/Loss = SP − CP; Percentage = (Profit/Loss ÷ CP) × 100
CP ₹800, SP ₹950: Profit = ₹150, Profit% = (150 ÷ 800) × 100 = 18.75%.
A positive SP − CP value is a profit; a negative value is a loss.
Cost price, the standard convention for profit/loss percentage.