26 calculators · 5 HP-41 modules · 1975–2023
Forty-year-old HPs still do the math. Here are the used HP and TI calculators worth buying, and what to check before you pay.
HP and Texas Instruments built calculators that people kept for decades, and plenty still work. A listing rarely says whether every key works, whether the battery has leaked, what it keeps in memory when it’s off, or whether it’s an original, a reissue or a clone. Each page covers one model, with its story, what it runs on, what to check in the listing and the eBay listings we’d buy.
A checklist for all 31 modelsFacts checked, sources listedNo affiliate links
Know the model? Start there.
model indexCalculator buyers shop by model number. Tap one to go straight to its page, or read the condition checklist first.
HP
- HP HP 12C
- HP HP 12C Platinum
- HP HP 12C Platinum 25th Anniversary
- HP HP 12C Prestige
- HP HP 17BII
- HP HP-10C
- HP HP-11C
- HP HP-15C (original)
- HP HP-16C Computer Scientist
- HP HP 15C Limited Edition
- HP HP 15C Collector's Edition
- HP HP-41C
- HP HP-41CV
- HP HP-41CX
- HP HP-25
- HP HP-27
- HP HP-29C
- HP HP-34C
- HP HP 32SII
- HP HP-42S
- HP HP-28S
- HP HP 48G
- HP HP 48GX
Find yours
browse byThe calculators people hunt for
HP
FinancialHP 12C
- Launched
- 1981
- Entry and display
- RPN · LCD
- Features
- Programmable · Keeps memory
$15–$35 typical ask
HP
VoyagerHP-15C (original)
- Launched
- 1982
- Entry and display
- RPN · LCD
- Features
- Programmable · Keeps memory
$95–$200 typical ask
HP
RPN programmableHP-41CX
- Launched
- 1983
- Entry and display
- RPN · LCD
- Features
- Programmable · Keeps memory · Mag cards · Plug-ins
$280–$460 typical ask
HP
RPN scientificHP-42S
- Launched
- 1988
- Entry and display
- RPN · LCD
- Features
- Programmable · Keeps memory
$190–$260 typical ask
HP
VoyagerHP-16C Computer Scientist
- Launched
- 1982
- Entry and display
- RPN · LCD
- Features
- Programmable · Keeps memory
$160–$280 typical ask
Texas Instruments
Algebraic programmableTI-59
- Launched
- 1977
- Entry and display
- Algebraic · LED
- Features
- Programmable · Mag cards · Plug-ins
$80–$160 typical ask
From our latest eBay check
TI-30 SLR+Vintage TI-30 SLR+Scientific Calculator W/Cover & Reference Card Works Dim
$7.00 deliveredCheapest
Checked Oct 15, 2026
TI-58CTexas Instruments TI-58C Calculator UNTESTED
$37.08 est. deliveredProject piece
Checked Oct 15, 2026
TI-59Texas Instruments TI-59 Programmable Calculator & PC-100C Printer Works No Key
$159.99 deliveredCheapest
Checked Oct 15, 2026
HP 48GXHP 48GX 128K RAM Graphing Calculator Original Case Tested Working Vintage
$211.69 est. deliveredCheapest
Checked Oct 15, 2026
Buying guides
5 guidesQuestions buyers ask
FAQWhich used calculators can I take into the CFA exam?
Only two models: the TI BA II Plus, including the Professional, and the HP 12C, including the 12C Platinum, the Platinum 25th Anniversary Edition, the 30th Anniversary Edition and the Prestige. That's the CFA Institute's policy as updated in January 2026. A used 12C of any year qualifies, but check the policy page again before your exam.
Can I use an HP calculator on the actuarial exams?
Not on the Society of Actuaries exams. The SOA allows only Texas Instruments models: the BA-35, the BA II Plus and BA II Plus Professional, the TI-30Xa, the TI-30X II and the TI-30X MultiView. None of the vintage calculators here are on that list.
Is it safe to run an old LED calculator on its charger?
Only with a battery pack fitted. HP's HP-25 handbook warns that running it from the charger with the pack removed may damage it, the HP-29C service manual says the same, and TI's repair notes and Wikipedia warn the same for the TI-58 and TI-59. If the old pack is dead, replace it before you use the calculator.
How do I tell an original HP-15C from the reissues?
Open the battery door. The 1982 original takes three button cells; the 2011 Limited Edition and the 2023 Collector's Edition take two CR2032 coin cells. The Limited Edition says so under the HP logo, and the Collector's Edition says Collector's Edition on the front. Pressing g then MEM shows 19 46 0-0 on an original or an LE and 19 78 00-0 on a Collector's Edition.
Does the HP-41 have a card reader built in?
No. The card reader is a separate accessory, the HP 82104A, which plugs into port 4 on the top edge. A listing that includes one is selling two things, so check the reader on its own: ask whether it has read and written a card recently.
What does the C in HP-29C or HP-41C mean?
Continuous Memory. The calculator keeps its programs and data when you switch it off. The HP-25C of 1976 was the first calculator with it. TI's version, on the TI-58C, is called Constant Memory.
Are SwissMicros calculators real HPs?
No. SwissMicros makes modern calculators that copy HP models, like the DM15, DM16, DM41X and DM42, and they're well made, but they aren't HP products. The 2023 HP 15C Collector's Edition was made by HP's licensees Moravia Consulting and Royal Consumer Information Products, not SwissMicros. If a listing for an original doesn't show HP branding and the right batteries, ask.
Sell to us
Got an old HP or TI in a desk drawer?
Tell us what you have, with photos of the front, the display switched on and the battery compartment, whether every key works, what comes with it and your price. Our calculator expert will get back to you quickly with a cash offer if it’s a fit. No listing to write, no fees.