The age difference of 20 years between Karna and the Pandavas

When we read the Mahabharatha or see shows and serials based upon the pic, the general perception is that Karna and the Pandavas and Duryodhana were all about the same age. But going by the epic, this is quite impossible. 

The exact age difference between Karna and the rest of Kunti’s sons is not mentioned in the epic but if we just see how the story unfolded, we can make a good guess here.

Kunti got the boon of calling a God to her and getting a son from them when she was a child in her adopted father’s home. She got the boon from Durvasa, who knew the future and was aware that Kunti would need it later in life. In the Geeta Press version, the wording is such that we see she attained puberty just a while after the mantra was given by Durvasa. This would make it reasonable to assume that she was between 10- 13 years old at this point. 

Adi Parva- Sambhava Parva-

And the Rishi said, 'Those celestials that thou shall summon by this Mantra shall certainly approach thee and give thee children.' 'Thus addressed by the Brahmana, the amiable Kunti (Pritha) became curious, and in her maidenhood summoned the god Arka (Sun). And as soon as he pronounced the Mantra, she beheld that effulgent deity--that beholder of everything in the world--approaching her.

Kunti grew up but once she reached marriageable age (let’s assume, 17- 18 years, meaning Karna is now 5- 7 years old) no one came asking for her hand in marriage. The king would have waited a couple of years because we see the mention that no one came despite her being a desirable match. Shortly, her father Kuntibhoja invited all the kings to his kingdom and asked Kunti to select her husband. Kunti placed the garland around Pandu’s neck. By Kunti's marriage time, Karna would have grown a little more but still let's assume he is now 7 years old. 

Adi Parva- Sambhava Parva-

But though endued with beauty and youth and every womanly attribute, yet it so happened that no king asked-for her hand. Her father Kuntibhoja seeing this, invited, O best of monarchs, the princes and kings of other countries and desired his daughter to select her husband from among her guests. 

Bheeshma wanted Pandu to marry again and he went to the King of Madra and asked him to give his sister in marriage to Pandu. Let us assume a minimum of one year passed after Kunti- Pandu’s marriage so Karna is now   8 years old. Madri was married to Pandu too, as his second wife. Just 30 days after his marriage, Pandu set out to conquer the ‘world’. His military campaign was a long one, as per the epic.

• He first fought against some robber tribes who had been troubling the Kuru lands for a long time

• Then fought against Dhirga- the king of Magadha

• Then won over the Videhas in Mithila

• Then many other kings- Kasi, Sumbha, Pundra and then went on to fight many more who are not mentioned by name but are all described as ‘all kings’

Adi Parva- Sambhava Parva-

And Pandu, accompanied by such a strong force marched against various foes. And that tiger among men--that spreader of the fame of the Kurus--first subjugated the robber tribes of asarna. He next turned his army composed of innumerable elephants, cavalry, infantry, and charioteers, with standards of various colours against Dhirga--the ruler of the kingdom of Maghadha who was proud of his strength, and offended against numerous monarchs. And attacking him in his capital, Pandu slew him there, and took everything in his treasury and also vehicles and draught animals without number. He then marched into Mithila and subjugated the Videhas. And then, O bull among men, Pandu led his army against Kasi, Sumbha, and Pundra, and by the strength and prowess of his arms spread the fame of the Kurus. 

Keeping in mind that going from one kingdom to another itself would take a lot of time in those days, especially since he was taking a huge army with elephant forces, horses and foot soldiers along, we can safely assume this whole campaign would have taken at the very least some 5 years although 10 years is far more likely because he would cover both North and then go back down south. Assuming a minimum 5 year time lapse, Karna is now 13 years old.

(Note: It was Pandu, NOT Dhristrashtra who expanded the kingdom of Hastinapuri so Pandu’s sons have a fairly clear right to ask for the kingdom)

Pandu brought back a lot of wealth and Dhirtrasthra also performed five great sacrifices at which Pandu was present. Now arranging for these sacrifices, inviting royals and brahmanas, then doing the actual sacrifices and then distributing wealth and cows and property to all- it all would take a significant amount of time.

Adi Parva- Sambhava Parva-

And with the wealth acquired by that hero Dhritarashtra performed five great sacrifices that were equal unto a hundred great horse-sacrifices, at all of which the offerings to Brahmanas were by hundreds and thousands.

It is a fair assumption that each would have taken a year to complete but let us assume all of them together took 2 years to finish. Now, Karna is  15 years old.

A little while after the sacrifices were done, Pandu decided to retire to the forest with his wives. In the forest, the king and his wives spent a lot of time, enjoying each other’s company in the midst of nature.

It is during this time that Pandu kills the Rishi Kindama who is in the forest with his wife, both in the form of deers. The rishi curses him that if he touches his wife, he will die. Filled with remorse that he killed the rishi and also reeling under the curse, Pandu renounces the kingdom ad decides to become an ascetic. Kunti/ Madri decide to accompany him. The three of them travel to different holy places.

Adi Parva- Sambhava Parva-

"Meanwhile, the Kuru prince Pandu (after sending away his attendants) accompanied by his two wives and eating fruits and roots went to the mountains of Nagasata. He next went to Chaitraratha, and then crossed the Kalakuta, and finally, crossing the Himavat, he arrived at Gandhamadana. Protected by Mahabhutas, Siddhas, and great Rishis, Pandu lived, O king, sometimes on level ground and sometimes on mountain slopes. He then journeyed on to the lake of Indradyumna, whence crossing the mountains of Hansakuta, he went to the mountain of hundred peaks (Sata-sringa) and there continued to practise ascetic austerities.'"

They crossed several mountains and plains so we can assume that it took several years for them to complete this journey and get to this location where he starts thinking about progeny. Let us assume that at least 4 years have passed (again, this is a very conservative estimate given what all he has done in this time). 

It is at this point that he discusses this with Kunti, lamenting that those without sons cannot ascend to the higher regions. Now Karna is around 19 years of age.  

Kunti tells Pandu about the boon she has received in childhood from Durvasa and one his request, she summons Dharmaraja and Yudhisthira is born. Giving the one year for conception and until the birth., Yudishtira is born when Karna is 20 years old. A year later Bhima is born, then two years go by because Pandu undertakes penance for a year to please Indra before Kunti conceives Arjuna. 

3 years have passed since Yudisthira's birth and Arjuna is born, meaning Karna is 23 years old now. Then probably another year before the twins are born. 

It is fair enough to assume that Karna is at the very least 19- 20 years older than Yudishtira, 21- 22 years older than Duryodhana/ Bheema and 22- 23 years older than Arjuna.  

All excerpts from: https://www.sacred-texts.com/hin/maha/index.htm