# HP 42S calculator

8 Hacker News commenters recommended HP 42S calculator and 0 criticized it, November 2025 to November 2026. It was recommended in 4 of 13 months; owners who said how long report a median of 30 years (3 owners).

**Verdict:** Owners recommend the HP 42S for its satisfying tactile buttons and long life, with many reporting decades of reliable use. Battery replacement is the common caveat.

## Why people recommend it

- Still working decades later, durable (3 comments): "My HP-42S is still running strong 30 years later" ([source](https://news.ycombinator.com/item?id=48377962)) "The HP still works 31 years later." ([source](https://news.ycombinator.com/item?id=45893845)) "None of them have broken." ([source](https://news.ycombinator.com/item?id=48086072))
- Satisfying tactile, memorable button layout (2 comments): "Just an awesome calculator that still has that awesome tactile button feel." ([source](https://news.ycombinator.com/item?id=45890483)) "Satisfyingly-clicky real buttons in memorizable positions" ([source](https://news.ycombinator.com/item?id=46837087))
- Favorite calculator, used often (2 comments): "to this day is my all time favorite calculator" ([source](https://news.ycombinator.com/item?id=48377290)) "I have a 42 at home and use it very often" ([source](https://news.ycombinator.com/item?id=48375672))

## What people warn about

- Battery replacement is difficult (1 comments): "Replacing batteries was a big pain on the original." ([source](https://news.ycombinator.com/item?id=45891621))

## Alternatives hackers recommend

- [HP 15C](https://hackerapproved.com/p/hp-15c-calculator.md): 24 recommend
- [Casio S100X Japanese Lacquer Edition](https://hackerapproved.com/p/casio-s100x-japanese-lacquer-edition.md): 16 recommend
- [Casio calculator](https://hackerapproved.com/p/casio-calculator.md): 14 recommend
- [SwissMicros DM42n](https://hackerapproved.com/p/swissmicros-dm42n.md): 13 recommend
- [SwissMicros R47 RPN calculator](https://hackerapproved.com/p/r47-rpn-calculator.md): 11 recommend

## Where to get it

- [See price on Amazon](https://www.amazon.com/s?k=HP+42S+RPN+calculator&tag=hackerapprove-20) (affiliate link)

## Cite as

Hacker Approved, "HP 42S calculator", https://hackerapproved.com/p/hp-42s-calculator/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).