If you see your parents twice a year, the number of visits left is smaller than it feels. Two questions — their age, how often you visit — and the arithmetic, from India's official life tables. It runs in your browser; their age never reaches any server.
Expectation of life at age x (e_x) from India's Sample Registration System abridged life tables, 2016-20 vintage, combined rural and urban. e_x is the life-table AVERAGE of remaining years — not a median — so the tool says 'average, and many live longer'. The calculator interpolates linearly between the five-year pivots below and tapers gently past the table's open 85+ interval.
The figure is the life table's average of remaining years — many people live longer, some much longer. It is not a prediction about your mother or father; it is a way of noticing that "we visit every summer" is a countable plan, and that the count is yours to change. One more trip a year is the single biggest input in the arithmetic.
We already computed the public version — it is complete and stays free. Turn the number into a plan: Join DesiSquare and the Square remembers your dates, re-runs this when the rules change, and puts a credentialed human one message away.