HP 28S calculator
Shares rank 20 of 21 calculators by recommenders
People recommend it for its programmability, including a Lisp-like language, and for physical ergonomics that software calculator apps lack. One critic notes that HP should sell a replacement battery door.
People recommend it for its programmability, including a Lisp-like language, and for physical ergonomics that software calculator apps lack. One critic notes that HP should sell a replacement battery door.
6 people gave an opinion
- recommend it
- 5
- criticize it
- 1
- approval share
- 83%
Recommended in 4 of 13 months
- November 2025: recommended
- December 2025: not recommended
- January 2026: recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: not recommended
- May 2026: recommended
- June 2026: recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: not recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 5 people recommend itNeeds 10 or more, not met.
- 5 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 4 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Lisp-like programming language
“the first to implement a lisp-like programming language in a calculator”
Comment from 2 Jun 2026 in “HP re-releases classic computer science calculator: The HP-16C” Better ergonomics than software apps
“The ergonomics of these are so far superior to using software apps”
Comment from 31 Jan 2026 in “Ask HN: Do you still physical calculators?” Teaches programming concepts well
“It felt like magic dealing with concepts I hadn’t seen in the C compiler on my Amiga”
Comment from 7 May 2026 in “Boris Cherny: TI-83 Plus Basic Programming Tutorial (2004)” Early start in programming
“HP started my journey so to speak”
Comment from 3 Jun 2026 in “HP re-releases classic computer science calculator: The HP-16C”
What people warn about
Each mark is one comment
No replacement battery door
“HP should sell a replacement battery door.”
Comment from 2 Jun 2026 in “HP re-releases classic computer science calculator: The HP-16C”
Other calculators people recommend
The four most recommended other calculators, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Texas Instruments TI-84 Evo | 41 | 53 | 44% | 4 | 10 yrs7 owners | — |
| TI-89 calculator | 31 | 8 | 79% | 8 | 28 yrs4 owners | Approved |
| HP 15C | 24 | 6 | 80% | 5 | 41 yrs5 owners | Approved |
| TI-83 Plus | 21 | 8 | 72% | 6 | 30 yrs3 owners | Approved |
| HP 28S calculatorThis page | 5 | 1 | 83% | 4 | — | — |
What people said
5 of the 7 comments that mention it, newest first. Each links to the original comment.
“HP started my journey so to speak”
“HP should sell a replacement battery door.”
“the first to implement a lisp-like programming language in a calculator”
“It felt like magic dealing with concepts I hadn’t seen in the C compiler on my Amiga”
“The ergonomics of these are so far superior to using software apps”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.