My advice would be to do 1/2 the lesson price +£10 for each student. So if you charge £30, then each student pays £15 + £10 = £25 per hour, meaning that you earn in total £50 per hour for two students, or £75 per hour for three students. Pretty much the same as what Eliza says above🙂

Though I also take into account who is the bill payer, so if it is two siblings (meaning the parents are paying for both) I would charge it at the normal rate since to the bill payer it makes a big difference if it is £30 or £50 (so a £5 saving for each student doesn’t make much of a difference since they pay for both). With three students I wouldn’t imagine that is a problem, though other factors come into the equation for example what will you charge if two of the three turn up for a one lesson etc.