HP 35s Scientific Calculator


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UPC: 883585142859   Part: F2215AA#ABA


  • Get professional performance from HP’s ultimate RPN scientific programmable calculator—ideal for engineers, surveyors, college students, scientists and medical professionals. Scientific projects require accuracy, functionality and dependability for success. The HP 35s scientific programmable calculator delivers them—and more—with features that include 30KB user memory, your choice of RPN and algebraic entry-system logic, a convenient two-line display, and the time-saving HP Solve application.



  • RPN or algebraic entry-system logic, keystroke programming, HP Solve and 100 built-in functions, Large 2-line display with adjustable contrast, Single and two-variable statistics, linear regression and more, 30 KB of memory plus 800+ independent storage registers, Fraction mode plus fraction-to-decimal conversion, 42 built-in physical constants, plus a complete library of unit conversions, inverse functions, cube root, logarithms, exponents, factorials and more

Ideal for

  • Ideal for engineers, surveyors, college students, scientists and medical professionals.

Permitted for use on

  • Permitted for use on SAT Reasoning Test, SAT Subject Tests in Mathematics Level 1 and Level 2, ACT Mathematics Test, PSAT/NMSQT, AP Chemistry/Physics, PLAN, and EXPLORE.

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Internal specs

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Best used for

  • Engineering; Surveying; Science; Medicine

Permission usage

  • SAT Reasoning Test; SAT Subject Tests in Mathematics Level 1 and Level 2; ACT; PSAT/NMSQT; AP Chemistry/Physics; PLAN; EXPLORE

Built-in functions

  • Over 100

Memory registers

  • 800

Memory, standard

  • 30 KB


  • 2 x CR2032 batteries; battery life: 0.73 year @ 1 hr/day (approximately 9 months)

Power off memory protection

  • Yes

Auto power off

  • 10 minutes

External specs

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  • Adjustable contrast with 2 lines x 14 characters + indicators, 14 character dot matrix (5 x 7)

Display type

  • LCD

Dimensions (W x D x H)

  • 8.2 x 1.82 x 15.8 cm

  • 3.23 x 0.72 x 6.22 in


  • 125 g

  • 1 year warranty (may vary by region)

What's in the box

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  • Calculator, batteries, user manual, premium protective case

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Customer ratings and reviews for HP 35s Scientific Calculator

Rated 4 out of 5 by 35s basic technical handheld I've had a 35, 67 and a 41cv. I had to replace my 41cv (only lasted 22 years) and chose the 35s as I am now retired. The keys are crisp and the display ordinary. Ergonomics are acceptable. Pluses include: batteries, fraction calculations and stored constants. I was disappointed with the limited program labels, storage registers and base conversion. The simplistic built-in equation functions seem to be targeted to high school students or college freshmen and are of limited practical use in the field. (memories of 41application pacs). Overall a solid choice for basic number crunching but without data input or card storage, progamability is limited. August 23, 2008
Rated 4 out of 5 by Good but some features awkward I really like this calculator. The programmable features and overall features are good. There are 3 things that are very clumsy for me. I do technical drafting in the construction industry. I use triangulation a lot. Therefore I use the polar coordinate feature a lot. This gives me, with two sides, the hypotenuse and the angle which is less than or equal to 45 degrees. On all of the older models of calculators this feature worked with very few key strokes and you could use numbers in the stack or in memory with it. Now it requires many more keystrokes to extrapolate the desired results and can only be done with direct entry. 2nd, the execute program requires at least one more keystroke than before. 3rd the store key requires a prefix key. Unfortunately, for me, these are 3 features that I use all the time. I much preferred the HP32SII for these features. I really like the keypad and design of this calculator except as shown above. I did not like the HP33s keypad and layout. The keys wore out too quickly and were not comfortable to the hand. I could not trust my keyed in entries on the HP33s. July 15, 2008
Rated 5 out of 5 The Best Scientific Calc in Pocket Size Excellent 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. July 13, 2008
Rated 4 out of 5 by An early review I bought this calculator for my son as a first calculator that should last a good long time. I have read other reviews that took issue with the hexadecimal data entry. I couldn't believe it, but it's true, the hex digits A-F are not marked on the keyboard. You have to use SIN -> 1/X instead of the keys marked A-F. Hmmmm. The Gallon conversion is US only, there is no US/Imperial flag. Sorry to the countries that still use imperial Gallons. The fractional calculation feature is pretty cool, but when you convert from fraction to decimal notation it seems to do a pop and you loose your X register. Occasionally a value will not be able to be translated to fractional form, or the value will be completely wrong (0.75 -> 2/3), but setting it to decimal and back to fractional sets it right. Check your answers. The |-> blue and <-| yellow key really don't need the arrows. The blue and yellow functions are not beside each other like other HP keyboards. Generally it seems as though there was a lack of user testing before it went to production. This calculator has a simpler, more familiar, feel to the UI than my 50G. It is more like my 21, 41C or 67. It's a good calculator but if it had more pre-production testing it could have been great. June 12, 2008
Rated 5 out of 5 by Perfect combo of Functionality and Ease-Of-Use I bought the 35s because it looked somewhat like a HP67 or HP41 (my all time favorite calculators). I am very impressed. It does not try to do too much, and so it remains easy to learn, and easy to use. It still does FAR more than what I expect from a programmable scientific calculator. The Keystroke programmability allows you to easily record the keys you would use to solve a problem, and then play them back (like recording a macro in Excel). It also has looping and conditionals if your problem is more complicated. This is the best way to program a calculator, since it does not need you to keep on looking up syntax (like you would need to do on an HP49g). If your problem needs more memory or steps than keystroke programming allows, you are probably off writing software in Visual Studio for a PDA. Note that this calculator does not connect to a PC, so if you lose it’s memory, you cannot restore. This is not problem, since the memory is limited anyway. It is not meant to be an “All-in-one” device, like a PDA. Instead, it solves common problems easily and well. Negatives : I use the STO function every time I use the calculator, but for some reason this is not on a top level key – you need to press the blue function button first to get STO. Instead MODE, which I barely use once a month is a top level key !! Poor ergonomics when doing arithmetic in different bases. Good for base conversions, but too clunky for anything else. Positives : HP Solve – if you are not yet using this daily, you should be !! The best implementation of calculator fractions I have seen – very easy to use, and fully adjustable, too. Brilliant manual, full of examples and explanations. (why not ring-bound, HP? We don’t mind paying a bit extra to allow the manual to sit flat on a desk). (Beware – some of these calculators only come with a quick-reference-guide – in that case you need to download the manual) Excellent build quality, reminiscent of the first HP calculators, except now much lighter. Excellent key-press feel, with positive feedback. Well chosen conversion keys. April 27, 2008
Rated 4 out of 5 Good calculator, but still room for improvement The relatively new HP-35S is a nice improvement over previous model (HP-33S) and a step in the right direction. It seems that the marketing people who run HP have realized that there still is a demand for high-quality, reasonably prices calculators. Pros: The funcionality, build quality, case, etc. are good for current price-point. Of course, HP could design and build a better product, but it would come at a price. The design is much nicer than the previous model, and HP has corrected some of the quirks which were enoying in the HP-33S (location of the [ENTER] key, entry of complex numbers, limited number of memory registers for a 32kb memory). Cons: There are some ergonomic and functionality issues. They may or may not be important to some people, but it would be nice if HP could fix them for the next release of this product (and call it HP-35Sii). Here are the ones I noticed so far: - The location of some of the keys is confusing. For example, in the good, old HP-32Sii, all left-shifted functions in the top row were actually menus. Simple to remember and intuitive. In the HP-35S the functions that open selection menus are randomly distributed all over the keyboard. I'm sure that with time and practice I will learn their location, but the keyboard layout of some older HP calculators was more logical. - The polar-rectangular conversion functions have disappeared. I find it difficult to understand why would HP eliminate such basic and useful functions. Granted, one can use complex numbers formats to do the conversion, but the process is cumbersome, and extracting individual parts in rectangular mode is even more cumbersome. Of course, one can also write a simple program to get around this issue, but it still defies my logic why the functions are not there. - Operations in hexadecimal, octal and binary mode are very cumbersome, require too many keystrokes, and can easily be mixed up resulting in the infamous "SYNTAX ERROR" message. There are also some other details, that in my opinion are not real problems, but may be an issue for others. The input and operations in ALG-ebraic mode are done differently to a "normal" calculator. For example, to calculate 5 times sine of 30 deg. one have to type: 5 [x] [SIN] 30 [ENTER] while on a "normal" calculator one would type: 5 [x] 30 [SIN] [=] While this may seem a bit confusing in the beginning, the HP-35S mode is actually the correct way of doing things in the pre-fix notation. The real problem is that common calculators' operating system is a mix-up of pre- and post-fix notation. However, we have been using them so much that by now everybody accepts this aberration as something normal. But once you grasp the logic of the HP input, it is very intuitive. Actually the ALG-ebraic mode of the HP-35S is pretty useful. While RPN is still much more efficient for quick calculations, the advantage of the ALG mode is that now one can write a long equation, evaluate it, and easily got back to correct mistakes or re-evaluate the equation with different arguments. This was not possible in the previous execution of ALG mode in the HP-33S, and is more consistent with the notation and syntax of graphic calculators / computers. Now, with all the critique, I'm still happy that HP has brought back a quality calculator after a period of releasing products that frankly were an insult to the HP tradition. The HP-35S is a good, versatile, and powerfull tool for students, engineers, and scientist who want the convinience, functionality and computing power of a programmable pocket calculator without the cost and size of a graphing calculator. Hopefully, HP will fix the minor problems and release an updated version of the HP-35S, together with a next generation of powerful, quality and affordable calculators. April 23, 2008

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Owner support

Warranty information

This product is covered by the standard HP warranty

Support information

Support for this product is provided by HP Customer Care

Returns & exchange information

The HP Home & Home Office Store will accept returns or exchanges for this product up to 21 days after delivery

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