I used to work full time but left two years ago to look after my SEN child. My work have asked me to go back as a contractor, so I have some flexibility about when & how much I work. I've never been self employed, so I now need to figure out all the logistics. I plan to set up a sole trader and now I need to tell them how much my day rate will be (or rather, my hourly rate as I only plan to work 5-6 hours a day).
From googling I found a calculator which suggested I take my full time salary, add 30%, and divide by 220. This gives me a day rate of £325. Assuming a 7.5 hour day that gives £43 per hour.
I appreciate I'll need to keep back some money to pay for tax, do a self assessment each year, probably set up a separate bank account to track income & expenses and that I won't be getting any benefits like holiday pay, sick pay, pension etc. I don't actually expect to incur any expenses as I'll be working from home, just talking to clients and working on documents (although I know you can claim some electricity, internet etc as expenses when doing taxes).
Are there any other suggestions for how to calculate a day rate? Anything else I haven't thought of in terms of costs or extra considerations I should build in?