I did the same thing with building something in excel - I didn't think as hard about the retirement portion though and just matched it to my previous pension contributions from when I was employed, so that's a great addition.
One thing I have in my sheet that I find helpful: A comparison with an equivalent annual salary at an employer. For example I have a day rate that is a rough approximation to match the annual salary I'd like to have if I were employed by someone - taking into account that the day rate needs to include sick days, holidays, the employer's share of insurance and pension contributions that I now pay etc.
Yeah, that is a great idea! I tried building something like that, but didn't quite get it right. Maybe I should give it a second go.
I have also thought about adding a feature whereby you can ask the equivalent of "I would like to be able to pay myself X per month" and then be told how much you would need to bill per month. In a way it's the inverse of what the tool does today.
I did the same thing with building something in excel - I didn't think as hard about the retirement portion though and just matched it to my previous pension contributions from when I was employed, so that's a great addition.
One thing I have in my sheet that I find helpful: A comparison with an equivalent annual salary at an employer. For example I have a day rate that is a rough approximation to match the annual salary I'd like to have if I were employed by someone - taking into account that the day rate needs to include sick days, holidays, the employer's share of insurance and pension contributions that I now pay etc.