The monthly total is the sum of the monthly-billing prices in US dollars. The yearly figure is that sum times twelve. Where the source states an annual-billing price, a second yearly figure uses it, so you can see what switching to annual billing would cut.
Plans shown with “from” count their lowest tier, and per-seat plans count a single seat. Taxes are not included: Mistral, for one, states that its prices exclude them, and the amount depends on where you live.
What overlap means
Each plan in the data is listed for one or more uses: writing, coding, research, images. When two ticked plans share a use, the calculator names them. It is a prompt to check, not an instruction to cancel: a chat plan that includes a coding tool and a dedicated editor can both earn their place.
An example
Take a general assistant at $20, a second assistant at $20 kept after a trial, and a coding plan at $20: that is $720 a year, with two plans listed for writing. Tick your own set and look at the yearly number before the next renewal.