Calculation of material for finishing?

Question

WordPress

Hello Toasters!
The question is:
you need to attach an online calculator to the site for an approximate calculation of finishing and construction work.
looked towards ucalc. because the site on wordpress now stands WPCC calculator so it suits. but I don’t understand how easier it is to calculate running meters based on quadrature.
for example m.p. lining costs 60 rubles > quadrature 4x3 > you need to multiply 45 by 60 = 2700
all this was calculated manually. but I don’t understand how to set and what formula for the rest of the dimensions of the premises (after all, not everything is considered in mp. there are piece positions, etc.).
maybe there are some analogues of the smeta.ru program or similar estimated programs, but for free?
to set quadrature, positions in m.p. or pieces and get the result of not the price, but the required amount of material?
in short, I don’t know if anyone will understand or not .. but I’ll leave this question here)
thanks to everyone who doesn’t pass by)