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Old Dec 05, 2006, 09:22 AM
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e-flight calculators & propdata (compilation)

I will compile the calculators mentioned in this thread, in this first message. Please post broken/old/rotten links so I can fix/remove them.

First the links to prop- and motordatabases, then the list of calculators. There is some overlap, so be sure to check both lists.

1 - Motor- and prop-databases
  1. Motor Data - test bench data for several hundred brushless motors - RCG (sticky)
    The database, several selection options
  2. APC propeller performance data
  3. Flybrushless prop database
  4. Prof. Michael Selig's propdata and tools, a.o. APC props
  5. Aeronaut, APC & Slowflyprop
    → TM Configurator
    → Aeronaut, APC & Slowflyprop tabs
  6. Determining motor constants
    → motor constants
    Christo van der Merwe a.k.a. RCG user Skylar
  7. How to add tested motor data to Drive Calculator by Ken Myers (
    Collecting Motor Data for Input Into Drive Calculator
  8. Measuring Brushless Motor Resistance (Two Digital Meter Method) - WFF
  9. Practical diy dynamometer - RCG
  10. Several diy test rig designs, thrust and dynamoter
  11. Theory and profiles by dr. Helmut Quabeck
  12. The math behind calculators and motors.
    Brushless motors are just brushed motors with electronic commutation (the ESC) instead of mechanical commutation (the brushes). Math is identical for both types.

2 - Calculators
  1. Drive Calculator
    Motor analysis and computation of the complete power system.
    Christian Persson/Helmut Schenk, English & German, Windows/Mac/Linux
  2. Propellor Calculator
    Computes the performance data of propellers with a given geometry, notably in-flight thrust and power drain across the utilizable airspeed range.
    Helmut Schenk, English & German, Windows & Mac
    → propellor calculator (bottom of page)
  3. MM_calc
    Louis Fourdan, English
    → téléchargements (link at top of page)
    → moteurs
    → MM_calc
    → English or French version
    Aero-nuts freeware
  4. MM_Calc derivatives
    All 6 are on rep. websites and/or RC-Groups +
  5. Measuring motor power without standard props, by running the motor with a calibrated "stick" fitted in place of the propeller prop:
  6. eCalc (€/$)
    propCalc, xcopterCalc, fanCalc, heliCalc
    English, Deutsch, Čeština, 中文, Español, Português, Français, 日本語, فارسی, Polski, Pусский, Nederlands
    5$ a year subscription
    xcopterCalc tutorial
    propCalc tutorial
  7. User yomgui's calculator/optimizer, Excel based
  8. Motocalc (€/$)
  9. Elektro-Antrieb (German only, €/$)
    AFAIK the first e-flight calculator, by Wilhelm Geck.
    Site does not exist anymore.
  10. P-calc
  11. ElectriCalc
    Sid Kauffman - ElectriCalc Designer & Friend
  12. Mumtats, user vintage1
    MUMTATS IS HERE! For inveterate experimenters and motor builders
  13. user Rod Badcock's thrust-, prop- and motor-calculators
  14. WebOcalc and PowerCalc (Free Open Source Software)
    → software
    WebOCalc - Free, easy power system help!
  15. Adam One Motor/Prop calculator (freeware)
  16. Thrust calculator (freeware)
  17. Thrust calculator (freeware)
  18. Prof. Mark Drela's prop calculator
  19. Dr. Martin Hepperle's prop tools
    → Javaprop
  20. Jim Banner's (user jrb) calculator
  21. PropEngine, Jim Kitt a.k.a. Aeroplayin - RCG
    Power Systems for Extreme Flight Fanatics! - RCG
  22. RC E-Calc - Electric flight calculator for Android phones
  23. Flight Calc, for props, edf's and helis
    → support
    → tech support
    → Flight Calc
Vriendelijke groeten Ron
Cumulus MFC, Nijmegen, Nederland Drive Calculator group
diy brushless motor group diy motor building tips & tricks
Last edited by Ron van Sommeren; Dec 03, 2016 at 06:20 PM.
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Old Dec 05, 2006, 09:48 AM
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Old Dec 06, 2006, 02:20 PM
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Here is another one for thrust/rpm:

and another estimator:
Old Dec 19, 2007, 11:36 AM
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Brand dedicated Motor Calc


In the serie you have
MM_Calc (see Ron post #1) on electrofly
You have the cousins in any order
1) Scorpion Calc
here v3.66 (march 2016) :
SC v4 beta with plane wizard :
2) Dualsky Calc v3.24 04 march 2013
3) MotrolFly Calc 2.36 april 2009
4) ARC Calc post #373 pg 25
5) Aero-nuts Calc
6) Himax Calc
All 6 are on rep. websites and/or RC-Groups + electrofly
I update regularly

Louis (the author)
Last edited by Fourdan; Mar 05, 2016 at 06:46 PM. Reason: SC new version
Old Dec 19, 2007, 01:34 PM
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Here's my spreadsheet (have EDF version too); its helped me with these and others:
Old Dec 29, 2007, 01:52 PM
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Prof. Drela has recently released a windows version of QPORP, his motor/prop analysis software. I've found it much better at predictions and efficiency calcs, since it uses a much more advanced prop model (not just thrust coefficients). Here's an exerpt of the manual:

QPROP is an analysis program for predicting the performance
of propeller-motor combinations. Its intent is to provide
an alternative to the existing prop/motor simulation programs,
which use relatively simple propeller models, and assume
a brushed DC motor type. QPROP has a relatively sophisticated
and accurate prop aerodynamic model, and a general motor model
which can be implemented via a user-supplied subroutine
if necessary.

It's a little more complex than motocalc, but pretty simple to use once you climb the learning curve.
Old Jan 06, 2008, 03:12 AM
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Eagle Tree Spreadsheet

i rigged up this spreadsheet for use with my eagle tree micro logger (with temp and rpm expanders):

Excel Spreadsheet (freeware)
Example Spreadsheet (freeware)

it supports quick & simple copy/paste operation directly from the eagle tree software, and outputs thrust, efficiency, kV, Io, Rm, max efficiency, max power, pitch speed... pretty much everything. for kicks i included standard deviations for every number.

it is based on rod badcock's spreadsheet (see post #1), and includes a few other calculations based on these equations. keep in mind it's in beta stage at the moment, and i'm not 100% sure if it'll work with pre o2k3 excel. the example sheet shows what it looks like with all the data entered from a bench test i did on a custom bluewonder.

just like badcock's spreadsheet, both of these spreadsheets include macros, so you may have to modify your security settings for them to work properly.


[edit: i just found an error in the spreadsheet which will cause it to be inaccurate if the logger is set to record temperature in farenheit. it works perfectly with the logger set to celcius. i'm working on a temperature unit selector, but until i update use celsius please.]
Last edited by Truglodite; Jul 15, 2008 at 05:25 AM.
Old Jan 24, 2008, 09:10 PM
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Nice converter program:
Last edited by BlazerB52; Jan 24, 2008 at 09:17 PM.
Old Mar 07, 2008, 09:04 AM
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Carlos Reyes - new free model airplane calculator

My new free online calculator (
  • designs efficient electric power systems
  • teaches you using interactive Tutorials and ToolTips
  • flies your model in a virtual wind tunnel
  • predicts airfoil performance
  • shows you the right tradeoffs for your scale model
  • displays graphs that update in real-time
  • runs on Windows, Linux and Mac OS X
Last edited by creyes123; Sep 09, 2008 at 09:50 PM.
Old Mar 28, 2008, 12:06 AM
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Carlos Reyes
My calculator ( includes the estimated Climb Rate. The Climb Angle seemed less useful. I don't provide feet/minute (easy to add), but I have MPH and feet/second among other units.
Old Jul 09, 2009, 05:45 PM
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Measuring motor power output using a calibrated dummy prop:

Vriendelijke groeten Ron
Last edited by Ron van Sommeren; Oct 15, 2009 at 04:16 PM.
Old Aug 08, 2009, 08:29 PM
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I'm in the process of moving all my "freeware", including MotorXLT2 and TurnCalculator3, to my blog for easier maintenance. Here's the link:

Note that I recently updated MotorXLT2 with my latest version, which includes calculations based on up to 4-props and no-load. This makes the calculations much more accurate. I also made the no-load page more "printer/screen grab" friendly, for easy posting of test results. Unfortunately, I still haven't got around to making a temperature unit selector, so you'll have to record temps in Celsius.

A general tip to those who benchmark:
Just like any other motor constant calculator, when setting up a series of tests you need to avoid using 2 props that are nearly identical (with respect to RPM, A, and V). Use of similar props often leads to inaccurate calculations of Rm, Kv, and Io. An example of this would be the apc5x5e and apc5.5x4.5e. While they fly very differently, both will give nearly identical RPM and current on the bench, which will confuse a motor calculator.

Old Oct 15, 2009, 02:38 PM
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Originally Posted by Ron van Sommeren
Measuring motor resistance without standard props, by using a dummy prop:
Post 11

Should read "measuring motor power output using a calibrated dummy prop".
Old Oct 15, 2009, 04:14 PM
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Brainfart Thank you Peter, I corrected it.

Vriendelijke groeten Ron
Old Mar 06, 2010, 09:53 PM
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What cracks me up about a lot of these calculators is they only have very expensive brands of components in the database.

Its like an advertisement. Nowadays things are great for the consumer, i've found some amazing good deals on very well engineered power systems, at about 1/10 the cost of hackers, scorpions, etc...certainly in the same performance ballpark at least.

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