Premium Membership ♕

Save 50% on all EEP Academy courses with Enterprise Membership Plan and study specialized LV/MV/HV technical articles & guides.

Home / Technical Articles / Calculating lightning strike distance

Lightning strike distance

Return stroke current magnitude and strike distance (length of the last stepped leader) are interrelated. A number of equations have been proposed for determining the striking distance.

The principal ones are as follows:

  1. S = 2 x I + 30(1−e − I / 6.8) –  Darveniza (1975)
  2. S = 10 x I0.65Love (1987; 1993)
  3. S = 9.4 x I2/3Whitehead (1974)
  4. S = 8 x I0.65IEEE (1985)
  5. S = 3.3 x I0.78Suzuki (1981)


S is the strike distance in meters
I is the return stroke current in kiloamperes

It may be disconcerting to note that the above equations vary by as much as a factor of 2:1. However, lightning investigators now tend to favor the shorter strike distances given by Equation 4.

Anderson, for example, who adopted Equation 2 in the 1975 edition of the Transmission Line Reference Book (1987), now feels that Equation 4 is more accurate.

FIGURE 1 - Probability of stroke current exceeding abscissa for strokes to flat ground.
FIGURE 1 - Probability of stroke current exceeding abscissa for strokes to flat ground.

Mousa (1988) also supports this form of the equation. The equation may also be stated as follows:

I = 0.041 x S1.54

SOURCE: Robert S. Nowell, Georgia Power Company

Premium Membership

Get access to premium HV/MV/LV technical articles, electrical engineering guides, research studies and much more! It helps you to shape up your technical skills in your everyday life as an electrical engineer.
More Information

Edvard Csanyi

Electrical engineer, programmer and founder of EEP. Highly specialized for design of LV/MV switchgears and LV high power busbar trunking (<6300A) in power substations, commercial buildings and industry facilities. Professional in AutoCAD programming.


  1. venu maheshwer
    Mar 21, 2015

    very use ful

Leave a Comment

Tell us what you're thinking. We care about your opinion! Please keep in mind that comments are moderated and rel="nofollow" is in use. So, please do not use a spammy keyword or a domain as your name, or it will be deleted. Let's have a professional and meaningful conversation instead. Thanks for dropping by!

  −  1  =  one

Learn How to Design Power Systems

Learn to design LV/MV/HV power systems through professional video courses. Lifetime access. Enjoy learning!

Subscribe to Weekly Newsletter

Subscribe to our Weekly Digest newsletter and receive free updates on new technical articles, video courses and guides (PDF).
EEP Academy Courses - A hand crafted cutting-edge electrical engineering knowledge