Get the flexibility no other scientific calculator can offer! Our 35s Scientific Calculator lets you choose RPN or algebraic entry-system logic (no other scientific calculator offers both). It also features a large, two-line alphanumeric display and adjustable contrast, plus a robust library of built-in functions and constants.
Choose RPN or algebraic entry-system logic
Work efficiently with the keystroke programming
Efficiently tackle heavy workloads with the 30KB memory and 800+ independent storage registers
Store an equation, then use it again to solve any variable using HP Solve, or employ any of 100 built-in functions
View entries, results, menus, and prompts with ease on the large, two-line display with adjustable contrast
Simplify physics with the 42 built-in physical constants
Get peace of mind with the one-year limited warranty plus HP Total Care advice and support
Specs Display size: 2 lines x 14 characters + indicators
Display Type: LCD
LCD: 14 character dot matrix (5 x 7) x 2 lines + indicators
Entry-system logic: RPN and Algebraic
Built-in functions: 100+
Menus, prompts, etc.: Yes
Internal precision: 15 digits
Memory: 800+ Memory registers; 30KB
Power: 2 x CR2032 batteries
Power off memory protection: Yes
Battery life: 0.73 year @ 1 hr/day (approximately 9 months)
Weight: 125 g (4.4 oz)
Size (L x W x D): 15.8 x 8.2 x 1.82 cm (6.22 x 3.23 x 0.72 in)
Enclosure material: Plastic, metal faceplate
Key top material: Plastic
Warranty: 1-year warranty (may vary by region)
Subject suitability: Engineering, Surveying, Science, Medicine
Permitted for use on: SAT® Reasoning and SAT® Subject TestsTM in Math 1 and 2, ACT, PSAT/NMSQT, AP Chemistry/Physics, PLAN, EXPLORE
What's in the box Calculator, batteries, user manual, premium protective case
HP 35s Scientific calculator is rated4.52 out of5 by42.
Rated 5 out of 5 byrcomeau from finally a calculator that matches the 32sIIThe only calculator in 20 years that matches the style and ease of use of the HP 32sII.
Date published: 2012-08-25T00:00:00-04:00
Rated 5 out of 5 byWolfdog from Waiting for the new 41CVThe 35s is a very practical and robust calculator for the professional. It handles arithmetic, statistics and moderately complex programming tasks very easily.The HP 35s has both RPN and standard algebra entry operation. In either mode, RPN or standard, this unit is highly refined. Users will find it to be very functional and powerful. It handles easy math to the more complex mathematics with ease.It incorporates features and functions that are easy to use and understand, yet has the power to complete some rather complex mathematics.The professional will find it to be very practical. The student will find it to be both rugged and powerful.It does not have graphing capabilities. It does, however, meet the needs and requirements for a robust, economical and practical solution for which calculators are intended.
Date published: 2008-04-13T00:00:00-04:00
Rated 5 out of 5 bykk001 from Need small versionI have used HP RPN calculators for 40 years and love them. I have published code for them in 170 countries for specific engineering applications. I have been waiting for 4 decades for a small version of a RPN calculator that will fit in my shirt pocket... yea, less programming function, etc... no problem... just need a smallish version to have with me all the time... never saw it... still hoping.
Date published: 2017-08-01T00:00:00-04:00
Rated 5 out of 5 bydday from HP 35s scientific calculatorThis calculator replaced my 48s that died. I never came close to using all the features, and this has all the features I need for quick calculations at my desk. I have grown up with HP and RPN way of entering numbers.
Date published: 2018-02-14T00:00:00-05:00
Rated 5 out of 5 byJasotTurbot from Love RPNI've been using HP RPN calculators for well over 20 years. In my opinion, any serious science or engineering student will be very well served by this device. This is the machine of choice in today's market.
Date published: 2017-07-21T00:00:00-04:00
Rated 5 out of 5 bymucraider from FINALLY!!Great to see HP coming back with the "standard" RPN format & keyboard again. I 'm still also using my favorite, the HP-42s. I'm really waiting for HP to re-release the HP-42 again. Does anyone have any word on this possibility?In the meantime, this is a great calculator
Date published: 2008-12-30T00:00:00-05:00
Rated 5 out of 5 byDrPangloss from great calculator, just a great calculatori've had an HP15 for 28 years and needed a second calculator for a second office. this one is made almost as well as the the bulletproof HP15. buttons feel good with tactile feedback. it has all the functions i want in a scientific calculator (well, it could have more complete built-in unit conversion). because it doesn't also try to be a handheld MS Excel device, the functions are easy to get to without having to dig through menus. there was no learning curve. it is simply an extremely good calculator.
Date published: 2011-01-12T00:00:00-05:00
Rated 5 out of 5 byDrJaysDad from The World's Best Pocket CalculatorIt's the best calculator in the world today!For anything more complex - use a spreadsheet.
Date published: 2009-09-17T00:00:00-04:00
Rated 5 out of 5 bydj81 from RPN still Rules!Love my HP RPN based Calculator. Considered old technology but still has a place
Date published: 2019-06-16T00:00:00-04:00
Rated 5 out of 5 byEngineer 100 from HP35Sthe calculator is OK but the 0 key doesn't always work. Sometimes I have to push it 2-3 times to enter a 0.
Date published: 2019-09-26T00:00:00-04:00
Rated 5 out of 5 bydedixon from Great HP35sI was happy to see the HP 35s introduced since I started using HP calculators and programmable calculators years ago. My first was HP 55 then HP 67 etc. I like the HP 35s for it's "simplicity" when I don't need graphing (which is more and more frequent now). The calculator does all I need, in the trusted RPN, and then much more. Simple programs are a charm. Thanks HP.
Date published: 2008-04-15T00:00:00-04:00
Rated 5 out of 5 byanrich from SolidNice and solid. I use it as a back-up. My primary hand calculator is, believe it or not, the original HP41 from the early 80's. After more than 25 years, it is STILL going strong!!!
Date published: 2009-03-11T00:00:00-04:00
Rated 5 out of 5 byBooy from Good BuyI like this calculator. It replaces a 33s and is very similar in usage. I wish that the 35s automatically seperated input numbers with commas to indicate 1000s as the 33s did. Otherwise, I am completely satisfied with the operation of this calculator.
Date published: 2011-10-29T00:00:00-04:00
Rated 5 out of 5 bySteevo from FinallyAn hp calculator in the true sense. Form and Function in the way that made hp famous. Good Job.
Date published: 2008-10-18T00:00:00-04:00
Rated 5 out of 5 byRHP22 from Excellent educational gift.I purchased the 35s as a gift for one of my former students. With this HP product, he can hone his skills further. He is already familiar with the 33s. His future for success is a little brighter.
Date published: 2019-12-24T00:00:00-05:00
Rated 5 out of 5 byLuke1 from Nice CalculatorWas hoping to replace my 42S but they are not made anymore. Only have couple days of use. The 36S is larger and lacks the quality feel of the 42S. Keyboard has crisper more tactile snap when key is pressed compared to 42S. Like being able to enter fractions directly, nice feature when adding or subtracting measurements. Fraction mode good is someone needs to borrow it.
Date published: 2020-03-05T00:00:00-05:00
Rated 5 out of 5 byKJC1953 from VEry Solid calculatorI've owned and used HP Engineering calculators for 40 years. This is another solid HP calculator with all the features you need.
Date published: 2020-03-02T00:00:00-05:00
Rated 5 out of 5 bynkeck72 from Good calculatorCould have better battery life, but all around a really solid calculator. Highly recommend for those looking for a new RPN calculator with the solid feel that HP has been known to deliver decade after decade.
Date published: 2019-09-20T00:00:00-04:00
Rated 5 out of 5 byRArman from HP 35sThe shape of this calculator remind me of my first HP calculator, the HP 41 CX, which I used through engineering school. Unlike the HP 41 CX, which I still have, the HP 35s feels much lighter, is slim and it feels right in your hands and the price is reasonable.
Date published: 2012-02-16T00:00:00-05:00
Rated 5 out of 5 bydavid991 from Excellent product!I have owned over a dozen HP calculators starting with the HP-35. The 35s and the 45 were/are the best of the lot.
Date published: 2013-01-20T00:00:00-05:00
Rated 5 out of 5 byMikeT3 from Just got it and love it.I bought this as the same time as the re-issued 15C. I gotta' say, this could become my new favorite. I love the retro look, it feels good, nice size and love the bigger keys. I just might have to get a couple more...
Date published: 2012-04-11T00:00:00-04:00
Rated 5 out of 5 byEarthlingEngineer2011 from The Best Right NowYou can read the many other reviews to learn about the shortcomings in the design and implementation of this product. Even with all of them, I'm very happy to have my new HP 35s. It brings back the feeling of HP's "golden years" of RPN calculator products.When HP reintroduces the HP 15c and HP 42s, I will happily throw my 35s into a box in the closet and buy each of those. But until then, this is the best next thing. To put it simply, this is the only decent scientific programmable calculator I could find that is currently manufactured.
Date published: 2011-08-10T00:00:00-04:00
Rated 5 out of 5 byRBRB from DisapointedApparently no Frac function for programming. BRING BACK THE 11C!
Date published: 2017-05-28T00:00:00-04:00
Rated 5 out of 5 byDaan Bosman from A very nice calculator. Love the RPN !I have owned HP calculators for over 30 years. I still have a 15c and also a 42s and a Prime graphing calculator. HP makes the best calculators, period. I just love RPN, it SO superior to using algebraic calculation. The 35s does it all. The keys are just right. It has a lot of functions, but most are visible in blue or yellow or white, and not hard to find.
Date published: 2020-02-02T00:00:00-05:00
Rated 5 out of 5 byCalmo from GreatThis is the closest I can come to the HP45 that got me through engineering physics. I worked two summers to raise the cash for the 45 back in the day. RPN, two line display, functions beyond 1975 imagination, and batteries that last 30 months, not three hours.Living science fiction.Cool.
Date published: 2012-05-11T00:00:00-04:00
Rated 5 out of 5 byjanczak4ever from Great Calculator!I like using this calculator because it is faster using RPN in place of standard notation. It does take some learning and patience to become used to it but once you get used to it you'll never want to go back to a standard calculator.
Date published: 2017-04-25T00:00:00-04:00
Rated 5 out of 5 byRandyR19 from I love the retro designI have owned many HP rpn calculators, I can't even use an algebraic calculator reliably. This is a wonderful little calculator in theory, but the quality is lacking, when compared to previous models. For a lack of alternatives, I just ordered my second one today. The buttons stick and aren't reliable. I hope I get a good one this time.
Date published: 2016-11-17T00:00:00-05:00
Rated 5 out of 5 byjon1948 from A Classic RPN CalculatorI grew up on RPN HP calculators. It's nice to see that HP sitll makes good RPN cacluators. I would strongly recommend the 35S to anyone that prefers RPN-style calculators.By the way, if you're trying to decide whether to buy a '33S or the 35S and you like RPN...buy the 35S. It's no contest! The RPN capability of the 33S is somewhat compromised. The 33s is a fine calculator but it's a better algebraic calculator.The only thing I wish the 35S had was a way to plug-in modules or download programs via USB. What would be fantastic would be to plug in USB memory sticks for storage of programs and data storage. If HP is listening...this feature is worth $20-30.
Date published: 2010-02-17T00:00:00-05:00
Rated 5 out of 5 byesse from this is it for RPNI bought several of these in case they stop making them or at leastcalculators like these. The 35s has a classic feel to it, and more featuresthan I'll ever need. Two lines of stack display is nice to have compared toclassic HP. The zipper clamshell is a nicer case to have; these camewith a sleeve type case from which you must fully remove the unit to use.Battery life just OK. Top edge of the screen (some tiny icons there)can be hard to see without good light at just the right angle. But Idon't think there's a better calculator, and for RPN I think it's the only gamein town (aside from the 33S which has a casio look to it, and a coupleof expensive HP graphing calculators).
Date published: 2011-08-26T00:00:00-04:00
Rated 5 out of 5 byryeguy from My Favorite Tool By FarI am a College Student who grew up with a dad who has been a loyal hp fan ever since his first calculator, The 41CX. My dad is an Electrical Engineer and he always helped me with my math. after a long time, I too have decided to follow the path to become an Electrical Engineer. When my dad found out he decided buy me my own hp calculator for College.Ever since the first time I got my hands on the hp 35s, I have not been able to put it down. Homework began to be fun due to my interest in learning to use it better, and have really grown in my confidence as a young mathematician.*The hp 35s is based around the "RPN" entry system rather than the "Algebraic" mode used by most other calculators (that aren't hp's).This entry system takes a little while to get used to, if your not familiar with it.- it took me around half a semester (3 months) to get comfortable with it-Great calculator, super powerful, awesome feel, beautiful to look at,all around it is my favorite tool for engineering by far!I seem to learn something new about it everyday.If you have previously owned an RPN hp calculator, consider this your back up.Great purchase.Thanks hp ;)
Date published: 2011-01-28T00:00:00-05:00
Rated 5 out of 5 byOld Technician from Fast and very capable.Recent purchase, so made in the Philippines and no keyboard errors. Very capable calculator with 10x more memory and much faster processing than older models. Crisp chicklets (keys). Longevity unknown, but less capable older models used extensively for 20+ years. Life and technology move on.Also own 30th anniversary 12C which operates flawlessly; very pleased with 12C and 15C apps. Very satisfied with the form and function of the purchases.
Date published: 2020-01-08T00:00:00-05:00
Rated 5 out of 5 byDoland from My HP 35sIt's great to know I can still get a calculator with RPN!
Date published: 2019-11-08T00:00:00-05:00
Rated 5 out of 5 byesauvas from good for surveyorsthis is a relly good instrument you have to check that out.
Date published: 2008-04-04T00:00:00-04:00
Rated 5 out of 5 byMichaelStrucEng from HP Classic CalculatorHP continues to make great calculators like they have for many years. This one works just like my first HP41 CV I bought in 1983. I was sold on HP products then and this New HP reinforces that satisfaction....Thanks and keep making great products.
Date published: 2011-08-29T00:00:00-04:00
Rated 5 out of 5 byDormanSilva from The Best Scientific Calc in Pocket SizeExcellent calculator for those people who don't want to carry outside the office of home the HP 50g. Excellent clamshell construction to protect the calculator.
Date published: 2008-07-14T00:00:00-04:00
Rated 5 out of 5 bybestsurveyor from not a good survey toolI have just gotten the 35s and started playing with it. I am not impressed at all in comparison to the 33s due mainly to the fact that the key stroke is to long for some of the simple functions such as polar req.. I think this function has to many key strokes for my field hands to be productive and to keep them from getting comfussed and the display of the distance and the angle on the same line is to easy to misread in a high pressure fast paced work envirment. I also noticed that my programs will have to be modified from the way they are imput into the calculator whereas when the switch was made from the 32s to the 33s there were no changes needed to them. This calculator will do everything you need to do but it just isn't user friendly which means a lot when you have people working for you in a fast paced high end industrial construction work place.
Date published: 2009-05-19T00:00:00-04:00
Rated 5 out of 5 byLarryJ from Great calculatorI have enjoyed this calculator, the features are really useful, does a lot of work for a small price. A great buy for anyone whe needs a scientific calculator.
Date published: 2011-10-13T00:00:00-04:00
Rated 5 out of 5 bySisyphus from A good, useful calculator for engineersThe HP35S is very light and the keyboard has a nice feel. It is somewhat cryptic to program but does have the solver functionality. Not quite as nice as the HP42S which is the gold standard for engineering calculators, in my opinion.
Date published: 2013-03-03T00:00:00-05:00
Rated 5 out of 5 byMark61 from Excellent Capability, so-so manufacturingI like this calculator, I actually have two. It is larger but easier to use than my 15c, I like seeing both the X and Y registers and the programming is easier too. The only problem is after a couple years the keys start giving out. I wish it was made better, especially with the $50 price tag. I also wish there was an android emulator. It could be much better with a little effort from HP to improve quality control and provide quality emulators.
Date published: 2016-06-21T00:00:00-04:00
Rated 5 out of 5 byKpflint42 from Effective Analysis ToolThis calculator is an effective replacement for the HP-33S . It combines programming power with multiple functions and good memory allocation for effective analysis of problems without needing a computer.
Date published: 2019-03-16T00:00:00-04:00
Rated 5 out of 5 bygeographer847 from Venerable RPN is great, but . . .I can't stand how often I have to replace the inconvenient CR2025 batteries. A real pain!
Date published: 2019-09-08T00:00:00-04:00
Rated 5 out of 5 byMy Sons from HP outpreforms All others for the money you pay!!!I have always loved HP Scientific Calculators and I love the HP 35s model as well. I am showing my age when I say; I used to have to load Engineering programs by keying the whole program by hand each time that I needed to use it. I just can't remember the model #. I won't live long enough to use the HP 35s to get maximum usage from it. I am 71 years OLD next month!!!