A reaction system for preparation of a viscoelastic polyurethane foam comprising: (a) a polyisocyanate component; (b) an isocyanate reactive component comprising: (i) from 35 to 74% by weight of the isocyanate reactive component of one or more propylene oxide rich (PO-rich) polyols having a combined number average equivalent weight from 200 to 500 and a polyoxypropylene content of at least 70 % by weight of the total mass of the one or more PO-rich polyols; (ii) from 24 to 50% by weight of the isocyanate reactive component of one or more ethylene oxide rich (EO-rich) polyols having a combined number average equivalent weight from 200 to 2,800 and a polyoxyethylene content of at least 70 % by weight of the total mass of the one or more EO-rich polyols; and (iii) from 2 to 10% by weight of the isocyanate reactive component of one or more butylene oxide rich (BO-rich) polyethers having a combined number average equivalent weight of 2,000 or more and a polyoxybutylene content of at least 70 % by weight of the mass of the one or more BO-rich polyethers, wherein the minimum amount of EO-rich polyol to use in the formulation ranges from 24 wt. % for equivalent weights less than 500 to 29 wt. % for equivalent weights greater than 1,000; (c) water; and (d) a catalyst component. (a) a polyisocyanate component; (b) an isocyanate reactive component comprising: (i) from 35 to 74% by weight of the isocyanate reactive component of one or more propylene oxide rich (PO-rich) polyols having a combined number average equivalent weight from 200 to 500 and a polyoxypropylene content of at least 70 % by weight of the total mass of the one or more PO-rich polyols; (ii) from 24 to 50% by weight of the isocyanate reactive component of one or more ethylene oxide rich (EO-rich) polyols having a combined number average equivalent weight from 200 to 2,800 and a polyoxyethylene content of at least 70 % by weight of the total mass of the one or more EO-rich polyols; and (iii) from 2 to 10% by weight of the isocyanate reactive component of one or more butylene oxide rich (BO-rich) polyethers having a combined number average equivalent weight of 2,000 or more and a polyoxybutylene content of at least 70 % by weight of the mass of the one or more BO-rich polyethers, wherein the minimum amount of EO-rich polyol to use in the formulation ranges from 24 wt. % for equivalent weights less than 500 to 29 wt. % for equivalent weights greater than 1,000; (i) from 35 to 74% by weight of the isocyanate reactive component of one or more propylene oxide rich (PO-rich) polyols having a combined number average equivalent weight from 200 to 500 and a polyoxypropylene content of at least 70 % by weight of the total mass of the one or more PO-rich polyols; (ii) from 24 to 50% by weight of the isocyanate reactive component of one or more ethylene oxide rich (EO-rich) polyols having a combined number average equivalent weight from 200 to 2,800 and a polyoxyethylene content of at least 70 % by weight of the total mass of the one or more EO-rich polyols; and (iii) from 2 to 10% by weight of the isocyanate reactive component of one or more butylene oxide rich (BO-rich) polyethers having a combined number average equivalent weight of 2,000 or more and a polyoxybutylene content of at least 70 % by weight of the mass of the one or more BO-rich polyethers, wherein the minimum amount of EO-rich polyol to use in the formulation ranges from 24 wt. % for equivalent weights less than 500 to 29 wt. % for equivalent weights greater than 1,000; (c) water; and (d) a catalyst component.