HP · Financial · September 1981 to today
HP introduced the 12C on September 1, 1981, alongside the 11C, and never stopped making it. It's HP's longest-running and best-selling product, and the de facto standard calculator in finance. The financial math inside came from William Kahan and Roy Martin. N, i, PV, PMT and FV sit across the top row, RPN does the rest, and the CFA Institute still allows it in the exam room. Over more than forty years HP has quietly rebuilt it many times: button cells until 2001, a coin cell after, an ARM chip running the original firmware from 2008. A 30th Anniversary Edition of 2011 was limited to 40,000. HP's licensee Moravia sells it new today, so used ones are about price and era.
Good forCFA examSurveying and real estateLearning RPN
Bench check
Should come with it
Check the listing photos against this list, and ask the seller about anything you can’t see. A missing piece should come off the price.
Few hardware faults are documented. Check for leaked button cells on older units, a display with every segment, and that it's a real HP rather than a clone.
New to old calculators? The condition checklist covers battery corrosion, displays, keys and card readers, and RPN in one hour gets you typing on an HP.
Buying guide
We'd buy the 12C titled tested with a leather case at $20 delivered, just under the $21 median. There are at least 439 for sale and working ones mostly ask $15 to $35 delivered, so there's no reason to pay more for a plain one. HP has built the 12C since 1981 and it's still sold new, so the battery door dates it, with three button cells before 2001 and coin cells after. Ask for a photo of the open battery bay with clean contacts and one of the display lit with every digit even. Skip the $508 listing with no seller shown, about 24 times the median.
$14.98est. delivered
The lowest delivered 12C titled tested, at $15, and the photo shows the display lit. No case is named, so expect a bare calculator.
HP Hewlett Packard HP-12C Financial Calculator- Tested & Works
$19.73est. delivered
Titled tested with a leather case at $20 delivered, just under the $21 median. Ask for a photo of the open battery door, which shows its era and any crust on the contacts.
Hewlett Packard HP 12C Financial Calculator W/ Leather Case Tested
$20.58est. delivered
The one to buy if you just want a working 12C for class or the CFA exam, since it's titled tested and arrives with new batteries. Ask for a photo of the display showing 0.00 with every digit even.
Vintage Hewlett Packard HP 12C Financial Calculator w/ New Batteries - Tested
$20.58est. delivered
Titled tested with new batteries, so it should work out of the box at $21 delivered. Only the calculator is named, so ask whether a case comes with it.
Vintage Hewlett Packard HP 12C Financial Calculator w/ New Batteries - Tested
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Snapshot
Checked . Some may have sold.
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Used$14.98est. delivered
$7.99 + $6.99 shipping
Buy It Now$7.99
Good buy
Titled tested and works. No case named; photo shows the display lit.
Seller: pantherandtiger
99.7% positive
Used$19.73est. delivered
$14.88 + $4.85 shipping
Buy It Now$14.88
Good buy
Titled tested, with a leather case.
Seller: han_7108
99.5% positive
Used$20.58est. delivered
$14.79 + $5.79 shipping
Buy It Now$14.79
Good buy
Titled tested, with new batteries. No case named.
Seller: thejoekewl
99.9% positive
Used$16.07est. delivered
$10.00 + $6.07 shipping
Auction · no bids yet · ends in 1d 13h
Our take
Titled working, with a case in the photo. Auction with no bids, so it will climb.
Seller: d_phadraig
100% positive
Used$17.79est. delivered
$11.99 + $5.80 shipping
Buy It Now$11.99
Our take
Titled tested working, with initials on it and no case. Photo shows every segment lit.
Seller: biggibba
100% positive
Used$20.92est. delivered
$14.99 + $5.93 shipping
Buy It Now$14.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
Titled 1986, made in Brazil and tested. Photo shows a slip case.
Seller: bluegrassofky
98.3% positive
Used$18.79est. delivered
$9.99 + $8.80 shipping
Buy It Now$9.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Check the seller
Same title as another seller's listing. Ask for photos of this unit and its serial label.
Seller: robowens
100% positive
Used$508.25delivered
$508.25 · free shipping
Buy It Now$508.25
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Priced high
No seller shown, and about 24 times the median. The title mentions a serial but doesn't give it.
Seller: Seller on eBay
Check feedback on the listing
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