HP · RPN scientific · 1976–1978
Every HP pocket calculator before the HP-27 did one job: science or business. The HP-27 of 1976, code name Salad, did both. Its 30 keys reach about 68 functions through yellow and black prefix keys, from trig and logs to statistics, time value of money and depreciation, with ten storage registers to work with. It can't store a program, which set it apart from the HP-25 next to it in the Woodstock line. Collector Tony Thimet rates its accuracy as excellent apart from the tangent near 90 degrees. It shares the red LED display and the two-cell NiCd pack of the other Woodstocks, and it was gone by late 1978.
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.
Dead packs and broken battery contacts are the usual Woodstock problems. It needs a pack fitted to run, even on the charger.
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
Only four HP-27s are for sale, asking $245 to $485 delivered, so treat that as four asks rather than a market price. We'd buy the one titled working with its manual, case and charger at $485 delivered, the only one here with a test claim, or offer on the $245 cased one if you're happy to fit a pack and test it yourself. The HP-27 won't run without a pack fitted, even on the charger, and an original 82019A pack is almost certainly dead, so ask whether a pack is included and plan on a new or rebuilt one, and ask about the battery contacts, which collectors report breaking off. Ask any seller for a photo of the display showing all 8s with every segment lit. The Argentina listing adds $60 shipping and a long wait, and its charger may not suit US voltage.
$420.70est. delivered
The cheapest HP-27 shown switched on, at $421 delivered with its original pouch. It has no test claim and no pack or charger named, so ask for all 8s on the display and whether the pack holds a charge.
HP27 Calculator Very Good Condition W/Original Pouch
$485.07est. delivered
The only HP-27 titled working, with the manual, case and charger, at $485 delivered. It can't run without a pack, so working implies one is fitted, but ask how long it holds a charge.
HP-27 Scientific Calculator, Good Condition; WORKING w/Manual, Case, Charger
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$420.70est. delivered
$400.00 + $20.70 shipping
Buy It Now$400.00
Good buy
Titled very good, with the original pouch. Photo shows the display lit; no test claim.
Seller: vtecnik420
100% positive
Used$485.07est. delivered
$449.27 + $35.80 shipping
Buy It Now$449.27
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, with manual, case and charger.
Seller: jones.sebago.lake
99.8% positive
Used$244.99delivered
$244.99 · free shipping
Buy It Now$244.99
Our take
Titled with a case, no test claim. Photo shows the display off.
Seller: mco-collectibles
99.6% positive
Used$450.00est. delivered
$390.00 + $60.00 shipping
Buy It Now$390.00
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.
Our take
Titled with the box, charger, manual and pouch. Ships from Argentina; ask about the charger's voltage.
Seller: alejandro.victor
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$170–$310 typical ask
HP
RPN programmable$440–$450 typical ask
HP
RPN programmable$370–$380 typical ask