Bigha (Punjab) to Bigha (Uttar Pradesh / Bihar, Pucca): the quick answer
To convert bigha (Punjab) to bigha (Uttar Pradesh / Bihar, pucca), multiply the value by 0.8. To go the other way, multiply bigha (Uttar Pradesh / Bihar, pucca) by 1.25 to get bigha (Punjab).
↔ Convert bigha (Uttar Pradesh / Bihar, pucca) to bigha (Punjab) instead