In Jainism, "biyashnu tapa" (also spelled as "biyashnu tap" or "biyashnu tapaḥ") refers to a type of austerity or penance observed by laypersons (śrāvakas) or sometimes by ascetics. The exact calculation of "punya" (merit) earned through any specific tapa (austerity) is not quantified in Jain scriptures in terms of specific units or amounts; rather, Jain texts emphasize the spiritual value and the intention (bhāva) behind the austerity.

The punya earned from biyashnu tapa depends on several factors, such as:

• Intent and Purity of Mind: Performing the tapa with pure intentions and a focus on reducing passions (kashayas) leads to greater punya.
• Strictness and Sincerity: Observing the rules of the tapa with discipline and devotion enhances the merit.
• Accompanied Austerities: If biyashnu tapa is accompanied by other practices like meditation, non-violence (ahimsa), and self-restraint, the punya increases.

Jain scriptures and commentaries often state that the true benefit of any tapa is the reduction of karmic bondage (bandha) and the accumulation of punya that aids in spiritual progress and better rebirths. However, the ultimate goal is to transcend both punya and paap (sin), and move towards liberation (moksha).

In summary: Jainism does not assign a specific amount of punya earned in biyashnu tapa, but regards it as a meritorious act, especially when performed with the right intentions and purity of mind. The true value lies in spiritual progress rather than quantifiable merit.