Electrical Calculations Sheet -Main

  • This Calculations Spreadsheets will determine the capacitor kVAR required to improve PF of a single load or entire power system. Actual power factor, peak kilowatt demand and desired PF are required. The best source of this information is the monthly utility bill or other local monitoring equipment. A calculation of each months data for a 12 month period is recommended to determine the maximum kVAR required. 


  • This Calculations Spreadsheets will calculate all the required values for a motor ( single or three phase) after putting the input information and can also calculate the wire and conduit sizes plus the voltage drop in these wires.


  • This transformer Calculations Spreadsheets will calculate the following:
    - Primary current, FLA
    - Secondary current, FLA
    - Primary Fuse Rating Max & Min
    - Secondary Breaker
    - Fault Duty, Primary
    - Fault Duty, Secondary
    - Calculated RMS Current, FLA
    - Calculated Harmonic Factor 

  • This lighting Calculations Spreadsheets will Estimate number of fixtures needed to light an indoor area based on room cavity method, these This lighting Calculations Spreadsheets are very useful tool for lighting design for both beginners and professional engineers.


  • This short circuit calculation spreadsheet estimates available fault currents for three phase systems. The calculation of motor contribution in this calculator is approximate only – systems with large motor contribution, high X/R conditions, and closed transition paralleled sources or high impedance grounding will require a more accurate calculation method.

  • The residential load calculation worksheet calculates the electrical demand load in accordance with NEC Article 220. The worksheet helps to provide an accurate, consistent, and simplified method of determining the minimum size electrical service for a new or existing dwelling looking to add additional electrical load. DEMAND load takes into account various probabilities of simultaneous operation of electrical appliances and yielding a safe, efficient and cost effective electric service. The Worksheet provides economic, as well as safety benefits. It helps to prevent oversizing service, which costs more money, and undersizing service, which is a safety/fire hazard.

This voltage drop calculator will provide an approximate value for use in project design and it is based on the following public domain formula and This spreadsheet includes three different worksheets as follows:
1-Voltage Drop Calculator worksheet
2-Summary worksheet
3-Information worksheet

IEC Motor Data Calculator spreadsheet includes three different worksheets as follows:
1- Motor calculator worksheet
2- Wire, cable and voltage drop calculator worksheet
3- Instruction and notes worksheet
I explained before the Motor Data Calculator as per NEMA standard products and today, I will explain another Motor Data Calculator but as per IEC code products.
in this Tools and Spreadsheets, I will explain the following:
Part One: What is selective coordination? 
Part Two: NEC code and Selective Coordination
Part Three: Method of performing a selectivity coordination study
  • First: By using Selective Coordination Time - Current Curves
  • second: By using Selective Coordination Charts/Tables.
  • By using Siemens calculators / spreadsheets.

These tools developed by GE to provide an analysis of a lighting system and are meant to assist users in reviewing certain lighting options. To perform an analysis, the tools make certain assumptions based on a variety of factors as shown in below. 
The GE Lighting Assistant 3.0 includes the following tools: 
  1. Cost of Light Tools 
  2. Lamp Performance 
  3. Group Relamping 
  4. Selling Aids 
  5. Energy Policy Act 
  6. Lighting Layouts 
  7. Retrofit Options 
  8. Scotopic Photopic 
  9. Internet Links 
  10. Other Tools




When opening the calculator, the first screen will provide six navigation options as follow:
  1. Residential lighting calculator NCC volume two, class 2 SOUs and class 4 parts
  2. Non Residential lighting calculator NCC volume one
  3. Illumination power density adjustment factors for a control device
  4. Multiple lighting system calculator NCC Volume one
  5. Help Screen
  6. Worksheet Screen
  • Total Demand  load Calculators for Buildings


These Calculators are the most professional Excel Sheet for calculating the Total Demand Load for all types of Buildings as per NEC Code.


These excel Sheets are exclusive for our website Electrical Know how, you will not find it anywhere in the web.

The benefits of using this sheet than other similar ones are as follows:
  1. It explains all the NEC rules applied for each calculation step inside the sheet.
  2. It is the most applicable calculator for all types of Buildings.
  3. It is the easy one for understanding and application.
  4. Some Demand Factors Tables are included in the excel sheet and no need to manually extract its data from the code as other similar ones do.

download these excel Spreadsheets by Clicking the following links:





why Using This Excel Spreadsheet?
I recommend all electrical engineers to use this powerful excel spreadsheet because it has the following unique advantages than other similar ones:
  1. List all data that must be known in the starting of Grounding System Design Calculations for Domestic, Commercial and Industrial Premises like electrical utility data,
  2. List typical Values of Resistivity from BS 7430 and IEEE 142,
  3. List all applicable standards for Grounding System Design Calculations for Domestic, Commercial and Industrial Premises,
  4. List acceptable values for Earthing Resistance,
  5. Calculate Soil Resistivity by using ground testers that apply The Wenner 4-Point Method,
  6. Provide a professional design concept for any Grounding System,
  7. List the Steps for Choosing the Best Earthing System,
  8. Provide grounding installation criteria for earth electrodes, earth pit, ground buses, grounding conductors, grounding of switches/ panels/ boxes/ cable trays / conduits and special grounding for high tension cables/ control cables /static electricity,
  9. Make (12) nos. different calculations for different cases, shapes and types of earth electrodes,
  10. Help you to specify all materials selected by grounding design process like Grounding conductors, Grounding stations and buried grounding mains,
  11. You can Print it as a professional calculations report for grounding system design for Domestic, commercial and industrial premises.




why Using This Excel Spreadsheet?
I recommend all electrical engineers to use this powerful excel spreadsheet because it has the following unique advantages than other similar ones:

  1. List all data that must be known in the starting of Grounding System Design Calculations for AC Substation ,
  2. Facilitate the design process by using the auto excel mathematical functions in performing the calculations,
  3. Provide a professional design concept for any Grounding System of AC Substation as per Standard IEEE 80-2000,
  4. Provide and make reference for all used equations from IEEE 80-2000 Standard,
  5. Provide a printable Results Summary Report.

Benefits For Using This Excel Spreadsheet
  1. List general data for designer and project,
  2. Calculate the collection areas for basic and adjacent structures, power lines (if any and up to two lines) and telecommunication line (if any),
  3. Calculate the collection areas for different shapes (Rectangular, cylindrical,…) basic and adjacent structures,
  4. List all input data (in green cells) that must be known to determine the need for lightning protection,
  5. Provide all tables of IEC 62305-2 as dropdown menus for automatic determination of parameter/factors values for the case under design,
  6. Provide two maps for assistance in determination of lightning ground flash density (Ng) and isokeraunic number (thunder storm days/year).
  7. Provide comments as a help guide which explains the meaning of the used parameters, factors and terms in this excel sheet.
  8. Provide the primary risk values automatically in the final results report and make a comparison with the tolerable risk values and assign the need for lightning protection based on this comparison for each type of loss.
  9. It saves time and effort lost in doing the calculations by the Manual Method (Equations and Tables Method) As we see in the previous Articles.
The Lightning Risk Calculator for Initial Screening is based on the Lightning Risk Assessment methodology of the NFPA 780 version 2011, the American Standard for the Installation of Lightning Protection Systems.
The risk assessment assists you in determining the need of a Lightning Protection System (LPS) and the risk of damage due to lightning.


This excel sheet used for the Calculations of Minimum Number of Plumbing Facilities Required in Electrical Water Heater Power Rating Calculation. It includes (4) sheets as follows:

  1. Cover and General data sheet,
  2. Floor input data sheet,
  3. Floor Calculation results sheet,
  4. Standard data sheet.