Electronic device and method of estimating bio-information using the same

An electronic device comprising:

• an optical sensor configured to emit a reference light to a reference object disposed on a charger and detect the reference light reflected from the reference object during calibration which occurs while a battery of the electronic device is being charged, and emit a measurement light to a target object and detect the measurement light reflected from the target object during a measurement;
• and
• a processor configured to, during a battery charging state of the electronic device, perform the calibration of the optical sensor while the electronic device is disposed to oppose or in contact with the reference object by controlling the optical sensor to emit to the reference object and detect the reference light, and after the battery charging state, estimate bio-information based on a light quantity of the measurement light that is reflected from the target object by the optical sensor, and a light quantity of the reference light reflected from the reference object.