ATMs in a tier-1 city
Transaction demand ÷ machine capacity, with a digital-payments twist.
Estimate the number of ATMs in an 8-million-person tier-1 city. Build cash-withdrawal demand, divide by per-machine capacity — and address the elephant: UPI has eaten most small transactions, but cash demand hasn't vanished.
Users
8M population → ~5.5M adults; ~80% have bank accounts with cards and occasionally withdraw → 4.4M users.
Frequency
Pre-UPI this was 4–6 withdrawals/month; today salaried users pull cash ~1–2×/month, cash-economy workers more → blended ~2/month → 8.8M/month ≈ 290K transactions/day.
Capacity
An ATM is economically viable at ~80–100 transactions/day (interchange fees vs rent + cash logistics + maintenance).
Count
290K ÷ 90 ≈ ~3,200 ATMs.
How to defend it
Acknowledge UPI explicitly and put it in the frequency assumption, not as a vague caveat. If pushed on "is the count rising or falling," reason from machine economics: falling transactions per machine push marginal ATMs below viability → consolidation.