approximation, estimate, estimation, idea - an approximate calculation of quantity or degree or worth; "an estimate of what it would cost"; "a rough idea how long it would take"
My fearless 'guestimate' is that more than a hundred billion pesos were spent in total by the current administration to help its allies, and by the tens of thousands of candidates who are running for a multitude of positions from councilor to senator all over the country.
His guestimate was of a thousand families out of the 30 million Pakistani families, just about the number of MNAs and MPAs who captured most of the state resources.
People who search on comparison websites for insurance are being warned by Money Saving Expert never to "guestimate" your information when comparing insurance quotes, even if it's just for a quick check.
As a "guestimate," it's not out of the question that Auxly deals with 250,000 kg of unique cannabis production - i.e., production that doesn't overlap with what was discussed above - via streaming and owned/partner grow sites, per year.
Depending on who you talk to, a rough guestimate leads to the conclusion that perhaps as many as a fifth of all new cars registered are not actually bought by a customer but taken as demonstrators, 'manager's specials' or whatever.