Body mass index = weight (kg) divided by the square of height (m). (The final index unit is kg/㎡)
Body mass index The result of body mass index calculation:
Normal weight: body mass index = 18-25 (China's physical fitness standard is 18-22 for women and 20-24 for men).
Overweight: body mass index = 25-30.
According to the height data you provided, 1.82m,
Body mass index (BMI) is calculated as follows:
The square of your body mass index = (70kg) ÷ (1.82) = 21.13, which is between (18-25) and (20-24).
So, your weight is normal and standard.
Don't worry!