Provided is a biological information measurement device, including: a blood index calculation unit which calculates at least part of a blood index associated with oxygen transport based on transmitted light or reflected light when a body part of a test subject is irradiated with light with a plurality of wavelengths an oxygen consumption calculation unit 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 unit which calculates a cardiac output based on a biological signal obtained by a noninvasive method from the test subject and an SvO2 estimation unit 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.