RANGES OF VALUES FOR "NORMAL" RESTING EKGs
(More or less common-denominator values from several sources; see references.)

	Normal		
EKG aspect or component	in mm (at
25 mm/sec)	seconds
(0.04/mm)	
heart rate -- in beats per minute: 60-100, or R-R peaks	25-15a	1-0.60	
                 -- regular R-Rs (irregular = arrhythmia)	all same b	all same	
ratio of P waves to R waves: should be 1:1 c	--	--	
width of P	2-<3	0.08-0.11	
distance from end of P to start of QRS (called the “PR segment”)	~1-3	0.03-0.12	
     or, above two added, from start of P to start of RS,
     which is called the "PR interval"	3-5	0.11-0.20	
width of Q (or, if no measurable Q, “0")	<1	< 0.03	
width of QRS complex	1.5-<3	0.06-0.11	
height (amplitude) of R (above baseline, with the baseline determined from between beats)	(variable, depending..)	(mVolts,
not time)	
depth of S (below baseline)
     (amplitude is affected by numerous factors)	(variable, depending..)	(mVolts,
not time)	
distance from end of S to start of T (called “ST”)
   (for diagnosis, start of Q to end of T, ventricular
   contraction + repolarization, or QT interval, is what
    is normally measured ... should be less than 1/2 R-R;
    also it is usually corrected [QTc] for heart rate, see refs.)	
(ST difficult
 	
to meas.)	
height or depth of ST segment above/below baseline	< 1-2 mm	--	
shape of T wave: should be asymmetric with gradual 
   incline, steeper decline	--	--	
total width of beat, from start of P to end of T	variable ...	...	
distance between beats, from end of T to start of next P, 
    or TP	varies with	heart rate	
Direction of peaks of P, R, and T waves in both leads I and aVF (preliminary view of heart's electrical axisd)	pointing upward	not appl	
a little boxes = 1mm, big boxes = 5mm, thus, the normal resting rate should be between 3-5 big boxes or 100-60 bpm [beats per minute] respectively. (As the rate increases during exercise, the normal R-R distance/time will become shorter.)
b there will be slight variation due to respiration (faster when inhale, slower when exhale).
c there may also be a "U" wave, an additional wave following the T wave, apparently normal in some people but not well understood, that may resemble an extra P wave, and can be confused with P waves, but is not a P (atrial contraction) wave.
d normal can be slightly different; the full, precise determination of axis requires information from the other leads also.
2007 J.W. Grier, may be copied and used without further permission