The Delhi Metro has been in the news, as it prepares to hike ticket fare even as it is facing strong opposition from the state government.

Delhi Metro fares are expected to rise by a maximum of Rs 10 from October 10, if the hike goes ahead as planned.

In spite of protests and opposition from political parties, the Delhi Metro Rail Corporation (DMRC) has remained adamant, saying that it is “necessary” to meet the operational input costs and calling the hike inevitable in order to “provide world class service to commuters”.

DMRC had made a net loss of Rs 378 crore in 2016-17.

The metro system, serving the National Capital Region (NCR), has seen no fare hike since 2009.

Delhi's metro, which also serves Faridabad, Gurugram, Noida and Ghaziabad in National Capital Region, is one of the cheapest in the country.

Currently, there are nine metro systems operational in India.

Here's a look at how the country's metro systems stack up on fares. We looked at the longest route that each citry's metro line offers and divided the ticket cost to the number of kilometres the train plies.

Average fare per km: Rs 0.98

With a total network length of 218 kilometres across colour-coded lines, the Delhi Metro is the largest of its kind in India. The maximum price of a single journey ticket on the Blue Line (50.56 km long) costs Rs 50, bringing the per kilometre cost to Rs 0.98 (at current prices).

Average fare per km: Rs 0.91

The 27.22-kilometre Kolkata Metro line is the oldest in the country and carries around 6.5 lakh passengers every day. It is India's second-busiest Metro system. The Kolkata Metro is also the cheapest in the country with average fare per kilometre coming to Rs 0.91.

Two of India's youngest metro systems — Kochi Metro and Lucknow Metro, run on 13.4 and 8.5-kilometre elevated sections, costing Rs 2.98 and Rs 2.62 per kilometre on a single journey.

Average fare per km: Rs 2.47

India's second largest metro network, Namma Metro (Bengaluru), saw its underground section being thrown open in June this year. For the 24.2 km Green Line, the average costs turns out to Rs 2.47 per kilometre.

Average fare per km: Rs 2.07

Running for just 9.63 km, the Jaipur Metro is currently India's second smallest metro network, behind Lucknow. A one-way journey on this short stretch costs Rs 2.07 per kilometre.

Chennai Metro, whose underground section was also thrown open in May this year, costs Rs 1.79 per kilometre on an average on the Green Line.

Gurgaon's 11.7-kilometre 'Rapid MetroRail' is costlier than Delhi Metro. Average fare for a kilometre-long ride would come to Rs 2.99.

Average fare per km: Rs 3.50

Mumbai's 11.4-kilometre fully-elevated line is the costliest in the country. A one-kilometre journey on the Mumbai metro could cost you Rs 3.5 on average. A single journey token could cost between Rs 10 to Rs 40 depending on the distance travelled.