[8] This is an area bounded on the west by Punjabi and Sindhi; on the south by Gujarati, Marathi, and Odia; on the east by Maithili and Bengali; and on the north by Nepali, Dogri, Kashmiri, Western Pahari and Tibetic languages.

These figures do not count 52 million Indians who considered their mother tongue to be "Urdu", which is mutually intelligible with Hindi.

There have been demands to include Awadhi, Bhojpuri, Kumaoni, Bundeli, Chhattisgarhi, Garhwali, Kudmali/Kurmali, Magahi, Nagpuri, and Rajasthani in the Eighth Schedule; these are otherwise regarded as dialects of Hindi by the government, although they have varying levels of mutual intelligibility with standard Hindi.

[16] Some academics oppose inclusion of Hindi dialects in the Eighth Schedule of the Constitution as full-fledged Indian languages.

Fiji Hindi is a derived form of Awadhi, Bhojpuri, and including some English and very few native Fijian words.

[21] The highly fertile, flat, alluvial Gangetic plain occupies the northern portion of the Hindi Heartland, the Vindhyas in Madhya Pradesh demarcate the southern boundary and the hills and dense forests of Jharkhand and Chhattisgarh lie in the east.

The region has a predominantly subtropical climate, with cool winters, hot summers and moderate monsoons.

Although the vast majority of the population is rural, significant urban cities include Chandigarh, Panchkula, Delhi, Lucknow, Kanpur, Raipur, Allahabad, Jaipur, Agra, Varanasi, Indore, Bhopal, Patna, Jamshedpur and Ranchi.