About & Pics


Build an AC or DC electrical circuit by adding, dragging and rotating components and then snapping them together. The steady state response is calculated instantly at the tap of a button. DC current flows can be animated on screen.

Zoom and pan around with standard gestures to view the voltages and currents which are displayed on the schematic.

Circuit Calculator is an ideal companion for anyone studying electrical engineering and is great for quickly checking your answers when you've solved a circuit analysis problem by hand. Enter component parameters as real and imaginary or modulus and argument, just as you would be given in a typical homework problem. Please note that this app doesn't perform transient analysis.

Main Features:

・Create your circuit schematic on screen
・Solve and show the results on the schematic
・Calculate steady state currents, voltages and power
・Show animated dc current flows
・Calculate Thévenin/Norton equivalent circuit values
・Choose polar or rectangular notation for AC
・Share circuits via Messages or Mail apps
・Print out your circuit
・Copy circuit to clipboard
・Load / save circuits on your device or in iCloud
・Undo / redo actions
・Copy / paste components
・Built in user guide

Available Components:

・Independent ideal current sources
・Independent ideal voltage sources
・Current controlled current sources
・Current controlled voltage sources
・Voltage controlled current sources
・Voltage controlled voltage sources
・Mutually coupled inductors - AC only
・Impedances - AC only
・Diodes - DC only

Check out http://circuitcalc.nwd-apps.co.uk or the Circuit Calculator YouTube channel for more information.

 $1.99 in iOS App Store


Circuit Calculator screenshot 1Circuit Calculator screenshot 2Circuit Calculator screenshot 3Circuit Calculator screenshot 4Circuit Calculator screenshot 5

Version History

Launched Mar 25, 2014 (about 5 years ago).

Releasing new versions every 2 months, on average.

Apr 20
Version 2.89

Minor improvements to user guide.

Dec 31
Version 2.87

Fixed a bug which under certain circumstances caused the app to crash in the Thévenin Equivalent Circuit calculation.

Dec 28
Version 2.86

Some amendments to user guide and other minor performance improvements.

Oct 24
Version 2.85

Some minor performance improvements to the quick start user guide. Added dynamic font support to component selector.

Oct 09
Version 2.84

Amendments to the quick start user guide.

Jul 19
Version 2.83

Added diode component for DC analysis. Added SI unit prefixes to DC component and results labels. Various other minor improvements. Please contact nwd.apps@gmail.com to report any issues or if you have any questions on using the app.

Jan 26
Version 2.82

Adjusted maximum level on iPhone for a double tap zoom. Please contact me at nwd.apps@gmail.com to report any issues or if you have any questions on using the app.

Dec 13
Version 2.81

Fixed a bug where editing a capacitor for a DC circuit showed the unit selector in Henrys not Farads. Please contact me at nwd.apps@gmail.com to report any issues or if you have any questions on using the app.

Nov 23
Version 2.8

Added animation for current flow in dc circuits. This feature can be enabled or disabled in the app settings. Various minor improvements in performance. Please contact me at nwd@nwd-apps.co.uk to report any issues or if you have any questions.

Nov 02
Version 2.7

Fixed a bug where loading previously saved files from the local device might crash the app if the user was not logged into iCloud. Please contact me at nwd@nwd-apps.co.uk to report any issues or if you have any questions.

Oct 29
Version 2.6

Fixed alignment of toolbar icons in vertical stack view. Please contact me at nwd@nwd-apps.co.uk to report any issues or if you have any questions.

Oct 24
Version 2.5

Thanks for using Circuit Calculator! This version includes the following updates:

・Added save to camera roll and airdrop share options.
・Added new file/network activity indicators.
・Minor amendments to user guide content.
・Various other minor fixes and improvements.

Please contact me at nwd@nwd-apps.co.uk to suggest potential improvements or report any issues.

Oct 11
Version 2.3

Fixed bug where saving a file to iCloud sometimes caused the app to crash.

Oct 09
Version 2.2

Added iCloud support so you can now access saved circuits across all of your devices.

Added some quick access shortcuts to the home page icon for force touch enabled devices.

Added a link via the toolbar action button to a set of tutorial videos.

Fixed an issue with resistor and connecting wires not showing properly on some devices.

Fixed keyboard scrolling on iPad in component editor, settings and file ops view controllers.

Fixed an issue where the the component data in mutual coupled inductors was not stored properly.

Various other minor improvements.

Sep 06
Version 2.1

Added a double tap gesture to the toolbar to toggle between a single toolbar which can be swiped left or right or all three toolbars in a vertical stack. Improvement to word wrapping on component labels.

Aug 30
Version 2.0

There are now two extra toolbars which replace the menu button in the previous version. Capacitors and inductors are now available components in DC analysis mode. AC power calculations have been added to the detailed analysis results. Long labels for component values, currents and voltage word wrap to the next line. A new copy and paste function has been added. A long press on the background no longer shows node labels as this now has it's own toolbar button. The circuit schematic can now be printed via the action button on the toolbar. Detailed analysis results can also be printed via a print button on the results page. Units have been added to the component value, voltage and current labels on the circuit schematic. New alert messages adjust their text size based on the user's system preferences and the content becomes scrollable if necessary. You can now zoom and scroll on the preview image in the load / save screen. There is a now radians or degrees option available via the settings page for the complex argument values used in the app. New image assets added for iPhone 6 Plus higher resolution display. Various other enhancements to performance.

Sep 26
Version 1.52

Fixed problem with node labels not displaying with new iOS 9 system font.

Sep 08
Version 1.5

Added new function to the main menu to find the Thevenin/Norton equivalent circuit voltage/current/impedance.

Jun 01
Version 1.4

Added a new menu item to the user guide linking to YouTube. This YouTube channel has videos on how to use the app.

May 15
Version 1.3

Some bug fixes and improvements to auto layout. Improvements to user guide.

Apr 07
Version 1.2.2

Modified user guide and other minor improvements.

Oct 08
Version 1.2.1

Fixed issue with keyboard covering text boxes on iOS 8 devices, fixed issue with menu button not working on iPad's running iOS 8, improved the detailed analysis page with text formatting and layout, added power calculation to detailed analysis page for DC circuits.

May 25
Version 1.2.0

Undo/redo functionality added (accessed via 2 finger long press gesture or shaking device). Improved recognition of ground node when near other components. Increased maximum zoom level on iPad to take full advantage of the larger screen size. Various other minor improvements.

Apr 26
Version 1.1.1

Fixed problem with ammeter component image not displaying properly.

Apr 14
Version 1.1.0

Enhanced graphics for retina displays, enhanced file system and various minor improvements.

Mar 24
Version 1.0

Previous 3 versions

Total Ratings


Total Ratings