Once you have measured your height and weight, you can calculate your BMI using an online tool, such as the NHS BMI calculator.
Pan fyddwch wedi mesur eich taldra a'ch pwysau, gallwch gyfrifo'ch BMI gan ddefnyddio offeryn ar-lein, megis cyfrifiannell BMI y GIG - https://www.nhs.uk/live-well/healthy-weight/bmi-calculator / .