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  1. 048Estimate how much cash is withdrawn from ATMs in India on an average day.Market sizing and estimationCoreIndian asset managementAsset management

    Try it first

    Which approach gives the strongest estimate in the room?

    Show the worked solution

    Roughly Rs 6,000 crore a day, on stated assumptions. Assume about 2.5 lakh ATMs, each handling about 80 withdrawals a day: 2 crore withdrawals. Check from demand: 30 crore regular users withdrawing twice a month is 60 crore a month, also about 2 crore a day. At an average of Rs 3,000 a withdrawal, the total is about Rs 6,000 crore a day. Confirm against published payment statistics for a real figure.

    Why build the count from the machines and from the people?

    If you wanted to know how many cups of tea a railway station sells, you could count the stalls and ask how many cups each pours, or count the passengers and ask how many buy one. A supply-side estimate and a demand-side estimate rest on different assumptions, so when they land close together, each one checks the other. Here both roads meet at about 2 crore withdrawals a day, which is the number that matters; the rupee value is one multiplication away.

    Two roads to the same count of withdrawals, then one multiplicationSupply side2.5 lakhATMsx80withdrawals a day eachDemand side30 croreregular ATM usersx2 a monthwithdrawals each/30days2 crorewithdrawals a dayxx Rs 3,000Rs 6,000 crorea dayTicket size is the loosest input:Rs 2,000Rs 4,000 croreRs 3,000Rs 6,000 croreRs 4,000Rs 8,000 crore
    2.5 lakh ATMs at 80 withdrawals a day and 30 crore users at two withdrawals a month both give about 2 crore withdrawals a day. At Rs 3,000 each that is about Rs 6,000 crore a day, and the ticket size alone moves the answer between Rs 4,000 crore and Rs 8,000 crore.

    Which assumptions need the most care?

    Every number here is an assumption to be stated, not a fact to be quoted. The average ticket size is the loosest input: Rs 2,000 against Rs 4,000 moves the answer from Rs 4,000 crore to Rs 8,000 crore a day, a factor of two. Withdrawals per machine vary widely, too, between a busy city branch and a rural machine, so treat 80 as an average across very different sites. The user count is the easiest to reason about from the number of adults with bank cards who still rely on cash.

    Say what would change the answer over time. Growth in digital payments lowers withdrawal counts; festivals, salary days and month ends raise them sharply, so an average day hides large swings. Converting to a year, about 365 times the daily figure, is a useful sanity check against any published annual total the interviewer might mention.

    For an asset management desk, the point is less the number than the method: a stock-and-flow structure, two independent builds, and a clear statement of which input you trust least. That is the same discipline as sizing a company's addressable market before building a revenue forecast.

    Where candidates lose it

    Candidates often start from currency in circulation, which is a stock of notes rather than a daily flow, or from the whole population, which counts people who never use an ATM. Both produce a number without a way to check it.

    Build it once from the machines, once from the users, and show they agree before multiplying by the ticket size. Then name the ticket size as the input you are least sure of.

    What the interviewer asks next

    • How would the estimate change on the day after salaries are paid?
    • How would you estimate the share of ATM withdrawals that digital payments have replaced?
    • How would a bank use this number to plan cash replenishment?