Look, if you still set your prices by copying the salon down the road, you're guessing. That is not calculating. The truth is, your price list should start with time.
A lot of people see a £40 service and think it must be better than a £20 one. Obviously not. If one service takes an hour and eats products, towels, water and your energy, and another takes 15 minutes with hardly any cost, the cheaper one can make you more money.
Simply put, divide the price by the time. Not in your head. Properly. Start with the service you do most. If your haircut is £40 and it takes 30 minutes, that gives you your baseline. Then check the rest of your menu against it. Very quickly, you will see which services are worth it and which ones are dragging you down.
And this is where people lie to themselves. They say, but clients in my area won't pay more. Maybe. But if a service takes too long for the money, you either raise the price, shorten the time, or stop pushing that service so hard. Honestly, there is no magic here.
Stop asking what others charge before you know what your own hour is worth. Until you know that, your prices are just random numbers.
I go into the full system in my book.