The Foreign, Commonwealth and Development Office said the assistance package would include ventilators and oxygen concentrators from surplus stocks.
It said the first of nine planeloads of kit would arrive in New Delhi early on Tuesday.
In a statement, Boris Johnson said: "We stand side by side with India as a friend and partner during what is a deeply concerning time in the fight against Covid-19.
"Vital medical equipment, including hundreds of oxygen concentrators and ventilators, is now on its way from the UK to India to support efforts to prevent the tragic loss of life from this terrible virus.
"We will continue to work closely with the Indian government during this difficult time and I'm determined to make sure that the UK does everything it can to support the international community in the global fight against (this) pandemic."
India has seen a steep increase in coronavirus cases in recent weeks, with the government and hospitals unprepared for a fresh surge after the easing of lockdown.
The discovery of a new ‘double mutant’ Covid-19 variant in the country has been blamed as one of the main factors for the rising cases, with the strain causing alarm because it has two spike proteins instead of one.
The variant is believed to be more transmissible than other strains and there are concerns it could render vaccines less effective, although this has not yet been confirmed.
The surge in cases has also been linked to lockdown restrictions being eased too quickly.
Several people have now died as a result of an oxygen shortage in Indian hospitals, with some families turning to social media pleading for oxygen supplies.
Additional reporting by PA.