Provided is a biological information measurement device (1), including: a blood index calculation section (12) which calculates at least part of a blood index associated with oxygen transport based on transmitted light or reflected light when an arbitrary body part of a test subject is irradiated with light with a plurality of wavelengths; an oxygen consumption calculation section (14) which calculates an oxygen consumption based on a gas concentration in inspired air, a gas concentration in expired air, and a ventilation amount of the test subject; a cardiac output calculation section (13) which calculates a cardiac output based on a biological signal acquired by a noninvasive method from the test subject; and an SvO2 estimation section (15) which estimates the mixed venous oxygen saturation of the test subject by substituting the blood index, the oxygen consumption, and the cardiac output in a calculation formula.