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 HP 35S So Far I'm a Civil Engineer and construction inspector and 25-year HP calculator user. I bought the 35S as a field calculator to replace my 20-year-old HP-48SX, and to allow me to put my mint-condition 22-year-old HP-41CX into semi-retirement at home and keep it out of the heat and dust. So far, I've been very happy with my purchase. The large numbers in the adjustable-contrast display are very legible. The two-line display is useful. Seeing the full 4-line stack is better but would take up more space. The keys have a nice, tactile feel and the large Enter button is a good, classic choice. The styling is beautiful, classic, almost Art-Deco, equaled only by the 12C, in my opinion. Like the 41 and 12C, the 35S has tall raised edges to protect the keyboard. It's very thin and light, making it a good fit for vest pocket or narrow storage spaces. That lightness may come at the expense of the tank-like build quality of the 48 and 10C series, but I've dropped my 35S out of said vest pocket 5 feet onto the pavement 4 times now with no ill effect. The CR2032 batteries no doubt contribute to the thinness. Though I'd prefer AAAs for easy availability, the CR2032 is the commonest watch-style battery and not hard to find. I'd also prefer a fully-enclosed case rather than the open one included with the 35s, to better keep out dust, but this case is sturdy and non-bulky and does protect the front and back well. My only issue with the construction is the soft, thin display screen, which allows even slight wiping pressure to momentarily darken the LCD display. I cut out a phone touch-screen protector and applied it to the display to provide some rigidity and additional protection. Honestly, most of my calculating is simple arithmetic, but I'm a dyed-in-the-wool RPN user (the choice of algebraic mode is wasted on me) that occasionally needs to use the calculator's more advanced capabilities. I haven't had the chance to do any programming, but am looking forward to seeing if I can translate some of my 41 programs for the 35S. The physical constant library is useful, as is the easy storage and recall of user data and the x-y register swap key. The Undo key is a nice feature, too. If you don't need graphing, or are an engineer that needs a good RPN calculator for field or daily work, I would recommend the 35S and would buy another. I like it a lot. June 30, 2011
Rated 5 out of 5 by HP-35s *DOES* convert rect --> polar The complex math capabilities allow both Cartesian and polar formats for both entry and display, with automatic conversion. Not obvious, though; it takes a bit of inference from the User's Manual, but it's actually very simple, and in fact more convenient than dedicated R>P, P>R function keys. I would highly recommend the 35s to anyone wanting a serious RPN calculator. [feel free to edit the following:] [I needed a replacement for my HP-32Sii, and was glad to see the 35s; they totally botched the ergonomics for the 33s with the stupid 'shiny' cosmetic treatment, it looks like a really lousy cellphone... Good thing someone came to their senses, and resurrected classic values instead of trendy flash-trash.] June 16, 2011
Rated 3 out of 5 by No Polar to Rectagle Function This calculator is missing a very important function; there is no polar to rectangle function. This is a critical function. It is available on the HP33. Can't imagine why they didn't include it in the HP35. Sending it back w/o even opening it! May 27, 2011
Rated 5 out of 5 by Best Scientific Calculator Going A welcome return to the classic HP model. As an engineering student, I find this calculator does exactly what I need it to do. February 13, 2011
Rated 1 out of 5 by Stuck with HP for RPN After using a HP 42s for many years I switched to a 35s after the 42 gave-up-the-ghost. Now I usually don't write reviews but my frustration has reached a level that has forced me to vent. The 35s, while full of nice features, has an HUGE drawback in that miss-keyed entries are a constant problem. With previous HP's miss-keyed entries were never a problem. With the 35s (and the 33s as I have read from other reviews) I am constantly having to key in equations again after the output makes no sense. And as far as I can tell there are no other scientific RPN calculators. I just ordered a Victor 12 RPN financial calculator so I can again proceed with my calculations with confidence. February 11, 2011
Rated 5 out of 5 by Good but incomplete The HP-35s is a great calculator in the tradition of RPN. Some caveats: 1. There is no built in polar-rectangular/rectangular-polar conversion. Yes, complex numbers provide a work around, and you can always program it or use the HP provided program, but it's really not the same. See 3 below. 2. Total membory of 30k? In this day and age, that's downright puny. 3. There is no capability of storage for programs, data, etc. That makes it a chore to reload programs. 4. The display can be hard to read. Strange considering the great displays that HP has had in the past. All in all, a great calculator, one that is a pleasure to use, with tremendous functionality. Especially likeable are the tactile keys. Just for context on this, I am a practicing EE, with over thirty five years of professional experience, and have been dealing with HP calculators since the HP-35. February 7, 2011

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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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