HP · RPN programmable · 1975–1978 (HP-25C 1976–1978)
The HP-25 arrived in 1975 as a cheaper, smaller way to program than HP's card-reading HP-65, and it was the first Woodstock that could run programs. HP's code name was Squash. It holds 49 steps and 8 storage registers, and it was the first HP to store a prefix and its function in one step, so those 49 go further than they sound. It was also the first calculator with an engineering display mode. There are no subroutines, just jumps to line numbers. In 1976 HP added the HP-25C, code name Squish, which keeps its program with the power off: the first calculator with battery-backed CMOS memory. Both have the red LED display and the two-cell NiCd pack every Woodstock shares.
Good forCollecting
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.
The pack is usually dead, the battery contacts break off, and running it on the charger with no pack can damage it. Sellers mix up the HP-25 and the HP-25C, which keeps its memory.
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 HP-25 titled fully functional with its case at $200 delivered, right at the $200 median and the cheapest one here sold as working. There are at least 23 for sale, many untested, and working ones mostly ask $170 to $310 delivered, so the boxed set at $468 is about 2.3 times the median. An original 82019A pack is almost certainly dead, so plan on a new or rebuilt one, never run it from the charger with the pack out (HP warns that can damage it), and ask about the battery contacts, which tend to break off. Ask for a photo of the display showing all 8s with every segment lit. A plain HP-25 forgets its program at switch-off, and only one with Continuous Memory in white script along the faceplate is the 25C that keeps it.
$199.99delivered
The lowest delivered HP-25 titled working, fully functional at $200 with its case. No charger or pack is named, so ask whether the pack holds a charge and plan on HP's charger or a replacement pack.
Hewlett Packard HP-25 Scientific RPN Calculator With Case FULLY FUNCTIONAL 💥
$199.99delivered
Titled fully functional with the case at the $200 median, about $135 less than the one with a new pack. Ask for a photo of the display showing all 8s and a look at the battery contacts.
Hewlett Packard HP-25 Scientific RPN Calculator With Case FULLY FUNCTIONAL 💥
$334.99est. delivered
Titled working and complete with a new battery pack, which is the part an old HP-25 almost always needs. At $335 delivered it's above the band, the price of not hunting for a pack.
Working HP-25 Scientific Calculator COMPLETE (Read Desc) New Battery Pack
$90.00delivered
Untested at $90 delivered, about $110 under the median. Pay parts money, since nothing says it powers on and no pack or charger is named.
VTG Hewlett Packard HP 25 Calculator UNTESTED
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$199.99delivered
$199.99 · free shipping
Buy It Now$199.99
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.
Good buy
Titled fully functional, with a case. No charger named.
Seller: ammich_74
99.7% positive
Open box$334.99est. delivered
$324.99 + $10.00 shipping
Buy It Now$324.99
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.
Good buy
Titled working and complete, with a new battery pack. The title says to read the description.
Seller: learjetpiano
100% positive
For parts$90.00delivered
$90.00 · free shipping
Buy It Now$90.00
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.
Project piece
Untested. Calculator only in the photo.
Seller: mikestorage
99.5% positive
Used$132.49est. delivered
$119.99 + $12.50 shipping
Buy It Now$119.99
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 with case, charger and manual, plus an ERDA stamp. No test claim.
Seller: ldmiller
100% positive
Used$294.04est. delivered
$274.99 + $19.05 shipping
Buy It Now$274.99
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
Sold as is, though titled powers on. Photo shows the box, case, charger and a reference card.
Seller: kingpiniii
100% positive
Used$308.51est. delivered
$296.99 + $11.52 shipping
Buy It Now$296.99
Our take
Titled works, with the owner's handbook and applications book. Photo shows a case too.
Seller: texgrandma
100% positive
Used$182.14est. delivered
$175.00 + $7.14 shipping
Buy It Now$175.00
Check the seller
Seller feedback is 92.9%. Titled with HP's soft case, no test claim.
Seller: rocks_retro_realm
92.9% positive
Used$467.85est. delivered
$450.00 + $17.85 shipping
Buy It Now$450.00
Priced high
Titled working, with the box and paperwork. About 2.3 times the median.
Seller: tri6bill
100% positive
Prices change daily. The live eBay search shows everything listed now, including anything new since Oct 15, 2026.
See every listing on eBay ↗eBay searchHP
RPN programmable$440–$450 typical ask
HP
RPN scientific$370–$460 typical ask
HP
RPN programmable$370–$380 typical ask
Texas Instruments
Algebraic programmable$40–$85 typical ask