PowerOne calculator 4+

Finance, scientific, and more

Crafty Weasel, LLC

Designed for iPad

    • 4.6 • 654 Ratings
    • Free
    • Offers In-App Purchases



Download hundreds of calculations or create your own with PowerOne® calculator.

• Several-time Apple staff pick + Best of 2010
• "The crème de la crème of calculators" – AppAdvice
• "Incredibly powerful tool for calculations of all kinds." – Smokin' Apps
• "You need this calculator. It's miles better than the competition." – Robert Burns
• "… sets the benchmark for other calculators to reach." – Fred Swan
• "Not sure how I could do my job without PowerOne." – Arvid Martin
• "A legend. The best … calculator app I have ever seen." – Worldwide Tech
• "… PowerOne shines." – The Mac Observer


• Quick and accurate. Templates act similar to locked-down, mini-spreadsheets that increase accuracy and speed for repetitive calculations. Enter the data you know. PowerOne will calculate the rest.

• For those one-off calculation needs, PowerOne provides a powerful standard and RPN calculator. Over a hundred functions to help with virtually anything: basic math, powers, logs, trigonometry, probability, programmer’s math, fractions, and Imperial and metric units.

• Get up and running fast with hundreds of pre-created templates in PowerOne's extensive library. Covers everything: finance, conversions, real estate, business, investing, construction, engineering, health, fitness, and more.

• While some calculations are common, there are millions more specific to you or your business. With PowerOne, it is easy to create powerful templates of your own using our intuitive language. You, your team, and your customers can perform their own calculations without ever having to think about the math.

• Access PowerOne everywhere. Whether on the go with your iPhone or iPad, on your M1 Mac, or at your desk on the web, PowerOne makes sure your critical calculations are available at your fingertips, offline or on.

• Keep everyone on the same page. Share your templates with your team and customers, ensuring that everyone is performing the same error-free calculations every single time.

• Highly customizable. Go beyond templates with expanded calculator functions and themes! Match your mood and make it the product you want to use every day.

After more than 25 years and over 30 million software calculators distributed, PowerOne has earned its reputation for high-quality apps. We'd love to hear from you. Please visit us at https://power.one, or share ideas, get help, and resolve problems by emailing us at help@power.one.


PowerOne uses anonymous accounts so we don't know who you are but still provide great benefits such as syncing across devices.


• Run PowerOne offline on your iPhone, iPad or M1 Mac
• Run PowerOne online at https://power.one
• Full-featured standard and RPN calculator (iOS only)
• Access to over 200 library templates
• Sample creating your own templates
• Share template results via email
• Go light or dark with your choice of two themes
• Keep your devices in sync automatically


• Over 300 library templates
• Create your own templates without limit
• Share templates with other Premium subscribers
• Access any of the built-in extensions to share or save your results
• Choose from 12 themes to customize PowerOne
• Support independent iOS developers and your favorite calculator's development!


PowerOne is free to use with some features available via monthly or annual subscription. Payment will be charged to your iTunes account at confirmation of purchase and your subscription will automatically renew unless auto-renew is disabled at least 24 hours before the end of the current subscription period. Automatic renewals will be charged at the same price you were originally charged for the subscription. Please note that subscriptions can be managed by choosing that option via Account within PowerOne or via Account Settings on the App Store after purchase.

Terms: https://power.one/terms
Privacy Policy: https://power.one/privacy

What’s New

Version 6.4.3

Bug fixes and improvements

Ratings and Reviews

4.6 out of 5
654 Ratings

654 Ratings

Finally-A-Great-App ,

Great app

I’ve been using PowerOne for many years now. I was in need of a good RPN calculator and liked their version 4 design. So I took a good look at the rest of the app and discovered the templates. What a discovery it turned out to be too. I’ve spent a lot of time and money on programmable calculators over the years and never found any that worked out. Until now, PowerOne is the definition of programmable, customizable what ever you want to call it. It’s just a lot fun to play around with and when you are done playing you have a powerful tool with you. It is too bad PowerOne is stuck in the calculator section of the App Store. It’s so much more than just a calculator. Although it does have a great calculator. However that’s just a small part of what PowerOne really is.

In Version 6 they brought back Version 4’s interface which was very easy to use and Version 6 is a lot easier to program than Version 4 was, so now we have the best of both versions.

I never had a problem with the login. Because I know what I’m getting in return. Things only a login can provide, syncing across all my devices, and a web based editor. Plus there are things coming in future versions I don’t even know about yet.

Pricing, I don’t understand how you can make money at a 1 time 5 dollar fee. It turns out you can’t. So if we want to keep using PowerOne the developer needs to get paid. The complainers have no idea of what they have. I do, and I’m willing to pay for it.

Wdav ,


Subscription services are lucrative for developers, I guess. But, for the user I have to decide which apps to subscribe to (if any) and which ones I have to quit using because I can’t afford a subscription for every app I use. I don’t mind buying an app at all, but having to pay an annual fee is just beyond my means. And so, I will switch my "calculator" app to something else other than PowerOne because they, at some point, will go to the next version (x.x or y.x or whatever) and I will be left in the dust having to subscribe to keep up with the technology. If every developer ends up with subscription requirements I will just have to abandon my support for them all. How many $50, $20, $75, $20, $40, $20, $25 services can you afford? For me it’s not many and so I just stop using an app that thinks their product should charge me a monthly or annual fee to use it!! There are plenty of alternatives out there. The smart developer will appreciate their customer’s PURCHASE of an app and take into consideration that users will have to decide which apps to keep or which apps to abandon. The less used apps I have will be the first to go. And, PowerOne falls into that category as there are many alternatives that don’t require a subscription fee after purchase.

I’ve paid enough for the prior versions of this app, remove ads. etc.

I’m done.

Developer Response ,

Hi Wdav,

I appreciate your position. I do want you to know that most of PowerOne is free to use. We include most of the templates and the entire calculator at no charge. We also now keep your templates and some of your calculations synced across devices and make a web version available to you when at your desk, all free.

We do have some premium features, and we do ask people to pay for those. But there is nothing that keeps you from using the free version forever.

Given that and given app economics, it has become clear that a subscription is the only way for PowerOne calculator to survive. We have purposely chosen not to use the kinds of intrusive and dirty tricks that other apps use. There are no ads, we don't sell our customer's data.

Hope you will continue using PowerOne.


Beny! ,

Great app! Always making it better... but... there’s the minus “-“ quirk

This is by far the best calculator app there is. Plus the versatility. But, there are always few little things and bugs to squash. There is an annoying thing about how it works after a result shows, if you press the “+” or the “*”, “/“ it will, obviously, invoque the “last” result plus the new operator pressed and it will let you continue with the operation, as expected, but if you press the “-“ it won’t apply that to the “last” but will start as a new operation. The other thing is that when you open a menu it constantly changes its height to accommodate the content. It cool, but it annoys the eye, but in this case, maybe it is just me. But trust me, this is the one and only calculator to have!

Developer Response ,

Hi Beny!

Thanks for the generally positive review. I did want to make sure you knew, though: the minus sign not invoking chain calculations is a known bug and will be fixed in the 6.1 release coming soon.


App Privacy

The developer, Crafty Weasel, LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • Usage Data

Privacy practices may vary, for example, based on the features you use or your age. Learn More

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